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FAQs on Mastacembelid, Spiny Eel Health/Disease

Related Articles: Spiny EelsThe truth about spiny eels; A closer look at these popular but problematic oddballs by Neale Monks, Husbandry of the Barred Spiny Eel, Macrognathus panacalus by Marco Lichtenberger, 

Related FAQs: Spiny Eels, Spiny Eel Identification, Spiny Eel Behavior, Spiny Eel Compatibility, Spiny Eel Selection, Spiny Eel Systems, Spiny Eel Feeding, Spiny Eel Reproduction,
By Species: Fire Eels, Peacock Eels,
Tire Track Eels,

Spiny Peacock eel fungus... Mis-stocking iatrogenic prob.s, no reading       5/3/15
<... what re the punctuation here? Are you a non-native speaker?>
first of all I'm resuming it the best I can, I'm using your saltwater question because sincerely, the website is confusing and the freshwater help, didn't help a little bit, I have just got 29 may, a peacock eel, it was in my 66gal tank, with 8 discus,
<Not compatible.... Mastacembelids like very different water quality than Symphysodon>
18 tetra neons, 7 ember tetra, 4 checkerboard cichlid, 1 Polypterus senegalus and 2 p. delhezi,
<.... What? You have Bichirs in here too? You need another few tanks to sort these disparate species out... READ on WWM re each species requirements and compatibilities. What you have here will NOT work>

and 4 gold sport dwarf Pleco (please don't bother me about number of fish in tank,
<You already know?>
as the discus will pair up they are going to 30g breeding tanks, the smaller fish(all but the Polypterus) are going to be relocated, the final fauna plan is to be 3 P.senegalus, 2 P.delhezi and the discus that don't pair(and hopefully the peacock eel)) It wa beaten bad, I don't know by whom, but it was, i didn't saw it since she was hiding most of the time in the
driftwood, until today morning she was normal, I was worried about her feeding habits, was giving Tetra ColorBits, frozen shrimp and a national fish food(name is Poytara, but they have no English website),
<Ahh; I see you are a NNS>
I didn't saw it eating so I just put some frozen shrimp at night and hoped it would eat when the others were not active, this morning it appeared almost upside down, I immediately separated it in a 15gal hospital with a (don't remember the English name, but the black pieces you put under gravel, though without gravel, just ceramic rings) and driftwood, put some national medicines (being one based in Acriflavine for fungus and one based in green malachite, Methylene blue, magnesium sulfate, potassium chlorate and copper sulfate that one for bacteria), am on my way to get some Melafix
<Worthless. READ before writing us... PLEASE!>

or anything they may offer at the best LFS around here,
and am wanting help as to what to do to try to save it's hale
<.... Let's have you start reading here: http://wetwebmedia.com/FWSubWebIndex/spinyeelsmonk.htm
and the linked files above. READ Gustavo... w/o your delving into matters here, your spiny eel and likely other fishes will perish. You need to separate them ASAP by their water quality needs and temperaments. Bob Fenner>
Re: Spiny Peacock eel fungus

Me again, just read that copper is no-good-idea for them, there should be about 0,015 grams of copper sulfate(30 drops = 1,5ml, there is 1g for 100ml in the medicine) in these 15gal, equal to 0,00025g of copper per liter, I am going to make a 5 gallon water change without the copper based medicine anyway, just wanted you to know
<You ARE reading! Good. BobF>
Fwd: Spiny Peacock eel fungus     6/4/15

Would you please elaborate WHY they should not be together ?
<... this TOO is archived on WWM. No need for me to re-key over and over>
"*Water requirements:* Soft, acid water preferred" taken from your link, discus also like soft and acid water (on that we agree right?)
<And quite warm...>

Where Polypterus are different, they can take a huge range of water parameters, I'd like to know why would it be a bad mix ?
<Simply that the group of fishes you listed don't have much overlap in preferences, tolerances...>
Also, it currently has the anti-fungus and MelaFix that I got earlier, it is still breathing but in bad shape, could the crew please first and foremost address the emergency and later talk about water param.s ?
BTW does NNS standa for Non Native Speaker or something else ?
<This is it; yes>
That's all, yes, I might have done some useless or dumb thing, it was my emergency protocol, do you have some better one to teach me ? Sorry by anu typo I made, writing in the cell while in a moving vehicle(I am not the driver, relax)
<Read or go elsewhere.
Bob Fenner>

Help with my spiny eel!     11/16/14
Hey guys! I have a problem with my Zig-Zag Eel i was hoping you could help me with. I noticed in one of your earlier posts someone was having a problem with his eels chasing each other and that his zigzag had a "protrusion" coming out that he wasn't sure if it was genitalia or not.
Well my eel has literally the exact same thing, but he also seems to be sick. His feces is more like a thick white mucous, and he seems to have these "spaz" attacks in which he'll rub himself against the gravel aggressively. He now seems to have a small bloodspot behind one of his gills, and i worry about infection. (i know now that gravel is bad for him, and I'm am currently working on fixing the issue. I am not able to remove all the gravel as i have live plants that need a strong substrate, so i think I'm going to clear a large area of the "floor" and build Plexiglas
borders that will create a box for me to fill with sand.
<Ah yes; or a plastic/glass tray of size that you can fill, fit in somewhere>
I think it would look nice and give him a good area to bury himself in, while still keeping some gravel for the plants.) Any help would be appreciated. He's still relatively small, about 3-4 inches. His tankmates are 1 angelfish, 1 Pleco, 5 neon tetra, 1 GloFish (rescue from a friend), and 1 elderly guppy. (retired from the breeder tank. lol) Thanks again guys!
<Welcome. Bob Fenner>

Help with my spiny eel!      11/16/14
Hey guys! I have a problem with my Zig-Zag Eel i was hoping you could help me with.
<Fire away.>
I noticed in one of your earlier posts someone was having a problem with his eels chasing each other and that his zigzag had a "protrusion" coming out that he wasn't sure if it was genitalia or not.
<Indeed. Oftentimes male fish have their visible 'spawning tubes' (genital papillae) some days before spawning, whereas those on females are hardly ever visible except at the precise time of spawning.>
Well my eel has literally the exact same thing, but he also seems to be sick.
<Ah, now that's different.>
His feces is more like a thick white mucous, and he seems to have these "spaz" attacks in which he'll rub himself against the gravel aggressively.
<Often/usually a sign of bacterial infection of the skin and/or protozoan infection of the skin/gills. Gravel is very bad for Spiny Eels, so their attempts to "rub off" the annoyance damages the skin, making bacterial infection even more likely. Things get worse and worse, eventually the Spiny Eel ends up red and bloody, then dies.>
He now seems to have a small bloodspot behind one of his gills, and i worry about infection. (i know now that gravel is bad for him, and I'm am currently working on fixing the issue. I am not able to remove all the gravel as i have live plants that need a strong substrate, so i think I'm going to clear a large area of the "floor" and build Plexiglas borders that will create a box for me to fill with sand. I think it would look nice and give him a good area to bury himself in, while still keeping some gravel for the plants.)
<Plants prefer sand. Gravel is useless to them. As one aquarist put it, when was the last time a gardener planted a rosebush in a gravel driveway?
Spiny Eels are somewhat incompatible with plants, so at the end of the day, choose to optimise the tank in one direction. That said, sturdy plants (Amazon Swords, Vallisneria, larger Cryptocoryne spp.) do just fine with
Spiny Eels, especially if planted first so they have time to root themselves in. A couple of pebbles placed on the sand around the plants will dissuade all but the most seriously industrious Spiny Eels from uprooting them. Floating plants and epiphytes attached to rocks (Java Fern, Anubias, etc.) are of course fine with Spiny Eels, and in fact floating plants are probably essential, both for their happiness and by preventing them from jumping out.>
Any help would be appreciated. He's still relatively small, about 3-4 inches. His tankmates are 1 angelfish, 1 Pleco, 5 neon tetra, 1 GloFish (rescue from a friend), and 1 elderly guppy. (retired from the breeder tank. lol) Thanks again guys!
<Much reading to do...
The routine addition of small amounts of salt (2-3 gram/litre) is an excellent idea with Spiny Eels and shouldn't cause problems for the Guppy at least, nor Common Plecs. The others won't be so happy about it. Salt at treatment levels for Whitespot (2 gram/litre) will be safe for all concerned across a 2-week period though. Antibiotics can be used to treat infections. Avoid copper and formalin. Good luck, Neale.>

Re: Help with my spiny eel!     11/23/14
Hey guys! Sorry it's taken so long to reply, but i took your advice. Few more questions though. So, i followed what you said and treated the tank with aquarium salt for a few days, and as of last night, i changed out ALL the gravel and replaced it with a sand substrate.
<Two useful steps.>
In order to change out the substrate, i had to remove all the fish and place them into my second 60 gal and then empty out all the of the water while removing the gravel. (only took me 5 hours! XD lol)
<Does indeed take a while! You can change the substrate with the fish in place though. Water will get murky however, and the fish won't be too happy (of course, they're not happy in a bucket or standby aquarium either).>
The second 60 gal already has fish in it, so i set up a divider to keep the two tanks away from each other. (it has an angel and 2 Plecos in it). Now i know that i completely disrupted the cycle and i was wondering how soon would it be safe to put them back into their tank?
<If you left the filter running while you changed the substrate, the filter bacteria should be fine. If you switched the filter off, removed the media and kept it damp or partially covered in water in a bucket open to the air, the bacteria will be fine for a day at least. If you switch the filter off, left the media damp but cooped up inside the filter with little access to fresh air, the bacteria start to die after 20 minutes (supposedly) and while some will remain, they'll be a bit knocked back in status when the filter is reconnected, so for the next day or two keep a close eye on water quality. If you switch the filter off and the bacteria dried out, then
you'll almost certainly have to start a whole new cycle (though dry bacteria spores in the media should speed things up to some degree).>
The tank that they're in is now overstocked, and i don't want to keep them in there for any longer than i have to. (the angels hate each other, and it's really cramped because of the divider.) I placed all of the old (unwashed) ornaments back into the tank, kept all the old filters in it, placed a plastic bag full of the old gravel into it to help with the BB, and treated the tank with aquarium bacteria i have from my first set up.
(also treated tank with SeaChem prime.) So basically my question is, how soon can i put at least the eel back into the tank, as well as the other fish.
<See above.>
And is it a good idea to put the Pleco back in their. seeing as none of the plants have had a chance to root and he's notorious for ripping everything up.
<Answered your own question there, I think. Common Plecs and plants don't really mix well; Ancistrus spp. are much better choices. Alternatively, choose plants that tolerate uprooting (Giant Vallisneria, once settled or started off in a pot seems to be one) or can't be uprooted, such as Java Fern attached to rocks.>
Thanks for yall's help, you guys literally have the best aquarium help site I've ever found and i will follow your instructions to the T. lol Thanks again yall! (one pic is of the new tank with the sand, the second pic is the tank all of the fish are currently staying in until it's safe to be returned.)
<Bright white sand will freak the fish out a bit to begin with because it reflects more light than gravel, so adding some floating Indian Fern will be a huge plus here, providing nice shade. Otherwise the upwelling light causes fish to "fade" their colours to blend in. Sand does age with time though, and over a few years (!) you'll notice it getting steadily darker.
Cheers, Neale.>

Re: Help with my spiny eel!     11/26/14
Ok cool! Thank you. Indian Fern is otw (had to order it as no lfs has any).
<Often the case. But do read Bob F's comments on this superb addition to almost any FW aquarium, here:
Always worth having some to share with other aquarists, too.>
But I do have one last question. I placed all my fish (except the Pleco) back into the aquarium and all seem to be doing fine. I also moved over my rainbow shark from the second tank and put him in with the others, since i wouldn't be moving over the Pleco. I figured it might help the tank seem a little less empty for now. The problem I'm having is the rainbow shark seems to be aggressive (mainly to the eel, angel, and tetras) and now I'm worried about my eel. I know eels don't shed their skin, but i found what looks to be exactly that on the "floor" of the tank. Could it possibly be his slime coat?
<To a degree, yes, but not as a visible "sheet" usually.>
Do they shed those as one whole piece like a snake?(visually of course).
and if so, what does it mean and should i be worried.
<Would wait a few days. Sometimes fish do odd things when their environment changes, such as shed mucous that traps silt, but a day or two later, they're fine again.>
I have since moved the rainbow shark back to his original tank with the Plecos (he won't mess with those big guys. They don't put up with it.)
<Indeed. The "fish we call sharks" are not really community safe, and best kept with bigger fish that won't take any nonsense. As you observe, the larger L-numbers will pay back any transgressions in kind!>
But I'm worried about the eel. Any answer is greatly appreciated.
<Give it a day or two before panicking. Turning down/off the lighting often helps a great deal. Check the Spiny Eel can't jump out though -- this is a critical phase, if he's not feeling settled. Write back if he hasn't settled down and/or isn't eating. Cheers, Neale.>

Unidentified Spiny Eel Fast Respirations     7/26/`14
Greetings Crew, I wanted to give you guys an update on my new Spiny Eels. I bought this 20g tank second hand(actually given to me), which included 2 eels, 2 Panda Corydoras and a pair of guppy. This tank is heavily planted with Elodea densa, Amazon swords, hornwort, Java moss and recently what looks like blanket weed(seems like a very tough algae to the touch)
<Most likely some type of Rhodophyta, colloquially "red algae". Difficult to eradicate directly; physical removal (of infected leaves/rocks), then prevention of further growth is what works. Favours tanks with indifferent plant growth, low to middling water currents, ample light, and medium to high nitrate levels. Rarely seen in tanks with lots of water movement, fast-growing plants (floating Indian Fern ideal for a quick fix) and sensible nitrate/phosphate levels.>
and thick sand substrate. I've never encountered this blanket weed before, but I'm trying to remove it from tank. I would say the blanket weed has taken about 5% of tank. This tank is only filtered by a HOB filter but I do 25% water changes every three days and keep nitrate almost at zero. This tank is unheated, but I just took a temp reading of 77.8F and PH of 8.1. My water supply is "hard".
The eels initially hid for about two weeks but come out regularly now.
Although I use a moonlight LED and still haven't got an ID on these guys but I will say they are peaceful to one another and Corys (very mellow). I have been feeding them guppy fry and red wiggler compost worms. Also tank is outside so they may get additional foods(lots of midges around). They are very plump.
<Do send along a photo if you can. Relatively few species are regularly traded -- Macrognathus siamensis (often as Macrognathus aculeatus), Mastacembelus favus (often as Mastacembelus armatus) and of course the famous Fire Eel, Mastacembelus erythrotaenia. But occasionally you'll see Macrognathus pancalus, Macrognathus aral, Macrognathus circumcinctus, Macrognathus mekongensis and various "Afromastacembelus" species from the Rift Valley and Congo.>
My concern is one of the eels is breathing rapidly.
<How warm is the water? Is there enough oxygen, specially at the bottom of the tank, an often overlooked aspect. Increasing/improving water circulation will help, and possibly adding extra aeration too (e.g., a spray bar or venturi). Is water chemistry odd for the species? Hard water should be fine for most provided it isn't extreme, but some are pickier than others. What's water quality like? None of the spiny eels is "hardy" in the aquarium sense of the word, despite being pretty adaptable creatures in the wild.>
He will raise his head out of sand for long periods of time. He has seemed active and is feeding. I was wondering if the tank was lacking oxygen but the other eel doesn't seem to show same symptoms. Could the blanket weed be irritating?
<Not as such, but may indicate lack of water flow.>
Also he doesn't show any outward sign of infection in any way. I'm hoping this isn't a parasite issue. What are your thoughts? Also should I eradicate blanket weed 100% or permit a little to grow?
<Rhodophyta are rarely welcome in aquaria, and rarely seen in stable, healthy aquarium; would review and act accordingly.>
Thanks for the great site. Aloha Brandon
<Most welcome. Neale.>
Re: Unidentified Spiny Eel Fast Respirations   7/27/14

Thank you for the timely response Neale. I did research Rhodophyta and luckily its not the one.
<Do recall that Red Algae, Rhodophyta, are so named because of how they appear when preserved, not in life. The freshwater species aren't red.
They're usually some shade of green in fact. Aquarium varieties of brush algae, hair algae and beard algae are all Red Algae, taxonomically speaking.>
This is a green algae that grows almost as little algae hairs that are actually branched. Seems very tough to tear apart. A few sites, mostly out of UK were calling it blanket weed, seemed to be a good match.
<Indeed, Cladophora spp; common pond species here. Not as often seen in aquaria as similar-looking Red Algae. The famous "Marimo Moss Balls" are very closely related, so if you know what the algae in these "plants" looks like, you'll recognise Cladophora. Fortunately, Cladophora are consumed by Siamese Algae Eaters, algae-eating shrimps, etc.>
Unfortunately I'm unable to sends pics, I've lost the connection to my camera. Thanks for your help. Brandon
<Welcome. Neale.>

eel is sick     7/4/14
Hi, I have a black spotted eel,
<A Mastacembelid... spiny (freshwater) eel>
I have attached pictures of it. It has some sort of growth in his mouth,
<Yes; looks tumorous>
he can’t close his mouth anymore, breathing very hard, behaving and eating normally. This has been there for a at least 2 months. I have never seen this before. He eats brine shrimp
<Variously nutritious... though I do eat popcorn most every night>
and frozen shrimp, in with cichlids. Hard water, an established tank. Is this something that can be treated?
<Not as far as I'm aware unfortunately. As with human growths of these sorts, the treatment options are limited to surgery, chemo-therapy... Most I would do would be ameliorative...>
Pls help,
<Will keep on WWM for Neale's reply. Bob Fenner>

eel is sick    /Neale's go    7/5/14
Hi, I have a black spotted eel, I have attached pictures of it.
<More commonly called the Tyre-Track Eel, Mastacembelus armatus -- though in fact it is possibly a related species, Mastacembelus favus.>
It has some sort of growth in his mouth, he can’t close his mouth anymore, breathing very hard, behaving and eating normally.
<Indeed. Clear damage to the mouth, bacterial secondary infection. Serious. Treat with antibiotics. Don't forget to remove carbon while in use.>
This has been there for a at least 2 months. I have never seen this before. He eats brine shrimp and frozen shrimp,
<Needs more variety than this; shrimp isn't a nutritious diet, too lacking in Thiamin and other vitamins. Earthworms a better choice, plus small pieces of tilapia fillet, seafood, etc.>
in with cichlids.
<What sort? Hopefully not "African Cichlids" in the Rift Valley, Mbuna sense. Tyre-Track Eels are somewhat predatory but not overtly aggressive (except towards their own kind) so are best kept with active midwater characins and barbs, for example Silver Dollars, Spanner Barbs, etc.>
Hard water, an established tank. Is this something that can be treated?
<Yes. See above. Do also review the aquarium. The substrate is one possible problem here. These Spiny Eels are easily damaged by gravel, and should only be kept in tanks with sand or very fine gravel.>
Pls help,
<Do read:


Virtually all problems with Spiny Eels come from shortcomings in the environment or diet. They're actually quite adaptable in all other regards.>
<Most welcome, Neale.>
Re: eel is sick
Thank you for your reply,
I will try to move him to a tank of his own today, I'll put some Epsom salt. What antibiotics should I use??
<Seachem KanaPlex is a good first choice. Unlike many other antibiotics, it's one of the better ones for treating external damage.>
I have general cure, but I don't think this will work. How much Epsom salt should I put per gallon?
<Epsom salt at 3 teaspoons per 5 US gallons/20 litres.>
He is in with African cichlids, they don't bother him at all, he's not predatory
<He should be! These fish can easily manage a Platy; made that mistake when I first kept one circa 1991. A mixed diet, with at least occasional white fish fillet pieces, is recommended.>
and he's pretty big and gets plenty of shrimp when I give it to him, 2 times week. Earthworms, I have plenty of those in the yard. Do I cut them up in pieces? Do they need to be washed? It's going to be a challenge though to feed him that.
<Feed whole. Choose the right size, drop in front, and Spiny Eels generally take them right away. Some soil on the body of the worm isn't a problem.>
The eel has been in the same aquarium set up for 5 yrs nothing new. The only thing I can think of, one day during a cleaning and water change I decided to take out the ornament he's been living in, I have rocks and this ornament doesn't fit in with the decore. So, he freaked out like crazy and burrowed himself under the huge and heavy rock pile, he did scrape himself pretty hard.
<A possible factor.>
But it all went away. the issue with his mouth was already present before the incident only now it's much worse looking.
The substrate is mixed in with round gravel and sand.
<Would remove gravel, replace with sand or very fine pea gravel.>
Sent from my iPad
<Sent from my computer. Cheers, Neale.>

Re: eel is sick      7/18/14
Hi, here's an update. I moved the eel to a tank of his own. He hasn't been eating for 3 weeks now.
<A bad sign.>
The medicine or the Epsom salt helped a bit with his issue, as the growth is not as big or as red.
<Good. Repeat/continue as possible.>
He's breathing very hard still.
<Optimise aeration and/or oxygenation as far as practical; robust circulation, supplemental aeration, etc.>
Unfortunately, it's not curing it.
<Indeed. I know Bob thought/think this cancerous, in which case a cure is unlikely; I'm not sure, but would bow to his greater experience.>
Do you have any other suggestions.
<A vet?>
Thanks, Ella
<Good luck, Neale.>

Re: eel is sick      7/22/14
Hello, my eel is still alive, and still not eating, probably 3-4 weeks now.
He has a cloudy eye on one side,
<Do read previous FAQs, here:
Epsom salt often useful.>
plus I noticed cottony growth on that growth in his mouth.
<Columnaris perhaps?>
What do I treat it with?
<Again, do read:
A bacterial infection, despite the "mouth fungus" moniker.>
Thanks, Ella
<Welcome, Neale.>

Peacock eel sick?    2/22/14
We have a peacock eel in a 60 gallon planted tank with gravel. We did try to make him a hiding area in the gravel with a pvc pipe, but he showed no interest.
<A faux rock or log works better>
 We have had him for several months and he has always been very energetic with activity and feeding. Yesterday, he started just laying at the bottom of the tank lethargically and seems to have stopped eating. We tried hand feeding him but he sort of shook his head and backed away (we have been able to hand feed him before). We have never done any live worms but often feed him the frozen blood worms.
<Unfortunately; these sewer fly larvae have such issues... Better to at least mix in some other foods>
 He also seems to be "breathing" heavy. We really love our atypical peacock and were hoping you'd have some advice as to whether or not he is sick
<Is sick... nutritionally>
 and if we can do anything to help him. We tested the water and everything was in the safe zones. Water temp stays between 76-78 degrees. We have community fish plus tiger barbs, a clown loach (to eat baby snails that we didn't know reproduced so well), and other bottom feeders.
-James Shelton-
<Do look into live or frozen/defrosted blackworms... Spiny eels (Mastacembelids) find them very hard to resist. Oh, and please peruse the archived files on this family of fishes on WWM. Bob Fenner>
Re: Peacock eel sick?    2/22/14

Thanks for the quick response.  We are making changes today.
<Ah good. BobF> 

Tire track eel with what I thought were scrapes     9/28/13
I have a one year old approx foot long tire track eel. He lives in a 125 with a group of rope fish a Senegal and three juvenile pair of Eartheaters.
The tank has two hob filters and two sponge filters due to the eel and the geo's need for clean water. The parameters are all spot on.
<Meaning what, precisely? Tyre-Track eels are best kept in neutral to slightly basic, moderately hard water; some would say slightly brackish conditions are useful too.>
The tank has been running for two years no problems.
My eel takes to pushing rocks around and making a ruckus. So we put bigger rocks we thought he wouldn't be able to move. And even siliconed them together with aquarium safe of course. But he woke me up the other night flinging rocks around and the next morning he had a white patch an the end of his nose and a patch on his side that looked like scuffs. I put him into a 40g hospital tank to be sure I can keep the tank star clean as to prevent infection. Now there is a spot of red in the center of the scrape on his side. Just looks like the scraped skin came off.
He is very active and friendly still not acting weird n any way but that he isn't eating. But I don't know if that is cus of the move or not.
I have treated him with a half dose off furan 2 because I was unsure if he needed or would be sensitive to medication. Any advice would be greatly appreciated.
Thank you,  Timbra
<Antibiotics are generally safe with Spiny Eels (certainly safer than copper and formalin) and should be used promptly where indicated. Spiny Eels often get damaged in tanks with rocks and gravel; they should be kept in tanks with smooth ornaments (ceramic tubes are great) and either very fine gravel or (ideally) sand. Once their skin is damaged, secondary infections are very common -- and often fatal. The addition of tonic salt at about 2 gram/litre seems to be useful and is often recommended. Ropefish and most cichlids will tolerate this just fine. Do read:    http://www.wetwebmedia.com/ca/volume_4/v4i3/Spiny_Eels/Spiny%20Eels.htm
And follow the links. Most problems with Spiny Eels are best avoided rather than treated. Cheers, Neale.>

Tyre track eel     9/30/13
This is my buddy we have been chatting about. As you know the Internet is almost useless when researching these guys to any major extent. He was sold to me as a tire track but I have always been skeptical of whether that is right or no. I have another eel the same size that is the typical dark brown reddish tire track you see and he just isn't the same. Any input?
Thanks a ton.
<Ah yes, it is one of the species sold as "Tyre-Track Eel" but precise species could be difficult to pin down. Often we call this fish Mastacembelus armatus, but another species, Mastacembelus favus, is very similar in size and shape, but with somewhat different markings. There are likely some other similar species, subspecies and/or regional variants. On the plus side, they're all very similar. Big (to 70 cm), predatory (made the mistake of keeping one with Swordtails!), somewhat jumpy (prone to escaping from aquaria), and arguably best kept in very slightly saline conditions (1-2 gram tonic salt/litre of water).>
P.s. that was the first day and he actually is looking much better. Still no appetite though. Well see.
<Indeed. Does seem to be an external bacterial infection. If at all possible remove to an aquarium without any ornaments or sand except for a ceramic pot, but failing that, do medicate appropriately (Maracyn 1 and Maracyn 2 would be a good combination) and keep water quality excellent.
Cheers, Neale.>
Re: Tyre track eel     9/30/13

Thanks for the info. It's much appreciated. That was the morning I woke to find him sick. He had since been moved to a bare bottom hospital tank with his pot. His course of meds is almost done and the spot on his nose is gone and the one on his side is all but gone. And his appetite is back with a vengeance lol. Thank you again for your help. You are a credit to the hobby.
<Thanks for the kind words, and hope this fishy friend gets well soon!

Spiny Eel Relationship Troubles; comp. f'      5/29/13
Hello again! Thank you for your advice with my 90 gallon tank setup.
<Glad WWM could help.>
Following it, I have decided to go with fresh water (80 degrees, planted) for this one. Currently stocked are two female Senegal bichirs, one male, (two are 4" one female is 6"), 4 leopard Ctenopoma (2-3"),  a brown and black ghost knife fish (5",4" respectively.
<All sounds good and broadly compatible, though do watch the Knifefish (they aren't famous for tolerating one another, to say the least).>
I'd consider this pairing a "test" as I'm not sure on how they'll get along, keeping a close eye, peaceful so far),
<Agreed. But since the African Knifefish is not an electric fish, the Black Ghost may well ignore it. On the other hand, both will be competing for the same sorts of lairs and food.>
Pseudotropheus socolofi (3" temporarily banished from my 40g cichlid tank),
<Doesn't belong.>
a high fin spotted Pleco for cleanup (3"),
<For now… if you're talking about Pterygoplichthys gibbiceps, these get massive, and quickly. We're talking 45 cm/18 inches within 2-3 years.>
and finally the focus of my troubles, a peacock eel and a Macrognathus circumcinctus
(so many common names for this one, what is the most widely used one?)
<I'd stick with the Latin names. Much more consistent.>
Both are 6-7", but the peacock is about half as rotund.
<Ah now, female Macrognathus are substantially deeper-bodied than males of similar length.>
First of all is this overstocked minus the cichlid?
<In 90 gallons, no, not at the moment, but I'd remove the Gibbiceps catfish anyway, since it's liable to compete strongly (too strongly) for foods such as bloodworms and krill that the Spiny Eels and Knifefish will need. If you wanted cats, I'd stick with something small and harmless, perhaps a trio of Synodontis nigriventris.>
I do have several other tanks I can put fish into if need be. Anyway, my main troubles are that both eels seem to like each other very much (they curl up together quite often, touch noses) but I have seen the Macrognathus circumcinctus chase the Peacock Eel twice today and bite his/her tail, recently causing a little tear.
<Does happen, as there is some territoriality once the males become sexually mature, but overall Macrognathus species are very tolerant of one another, especially in groups of 3+ specimens. This contrasts with Mastacembelus spp Spiny Eels that seem to be much more territorial and aggressive, sometimes lethally so.>
I figure it has something to do with either the heat, mating, or maybe just attitude problems.
Also should I remove the Peacock Eel?
<I don't think so; in 90 gallons they should come to some sort of accommodation, especially if there are plenty of floating plants (which are what the male Spiny Eels want most of all).>
The peacock has always been very delicate and shy, whereas the Mac is quite energetic and I wouldn't want to be responsible for him hurting her.
<I see. Try adding some more Peacock Eels.>
One last thing regarding the Macrognathus circumcinctus while I'm at it. I noticed since I rescued him (her?) That he has a not so subtle appendage near his rear. Is this a sexual reproductive organ?
<Not to my knowledge. Do be aware of what Camallanus worms look like, and act accordingly.>
I looked and looked and not one other Macrognathus circumcinctus (or any spiny eel for that matter) on an image search had this "appendage", my other spiny certainly does not. Again thank you so much for your time to help out the less knowledgeable. Regards, Austin
<Most welcome, Neale.>

Re: Spiny Eel Relationship Troubles (RMF, Marco -- genital papilla?) <<Don't think so. RMF>>     5/29/13
Good morning/afternoon. Thank you for the fast reply! All sounds swell, yes the cichlid is leaving that tank asap. Just wanted to give his tank mates a break and a chance to better establish their own territories. As for worms, I have checked and it does not even remotely resemble Camallanus worms (breath of relief).  I have included a cropped picture of it, as good of one as I can get. It's hard to see in the picture but it perfectly matches the Macrognathus circumcinctus' color markings, and it doesn't appear to be protruding from the anus.  Again any help with this trivial matter is still appreciated. Thanks, Austin.
<Do agree that this is an odd structure. Never seen this on my Spiny Eels.
A quick search on Google Scholar suggests that the genital papillae (or pores) on Mastacembelids tend to be quite small, which this isn't. But I didn't do an in-depth review, and without seeing pictures, it's hard to compare your specimen to others. Have CC'ed Bob F and Marco, who may know better. In any event, you could deworm as a preventative, but if the fish is fine and maintaining a healthy body weight, I wouldn't worry overmuch.
Cheers, Neale.>
Re: Spiny Eel Relationship Troubles  /Marco     5/29/13

Good morning/afternoon. Thank you for the fast reply! All sounds swell, yes the cichlid is leaving that tank asap. Just wanted to give his tank mates a break and a chance to better establish their own territories. As for worms, I have checked and it does not even remotely resemble Camallanus worms (breath of relief).  I have included a cropped picture of it, as good of one as I can get. It's hard to see in the picture but it perfectly matches the Macrognathus circumcinctus' color markings, and it doesn't appear to be protruding from the anus.  Again any help with this trivial matter is still appreciated. Thanks, Austin.
<Do agree that this is an odd structure. Never seen this on my Spiny Eels.
A quick search on Google Scholar suggests that the genital papillae (or pores) on Mastacembelids tend to be quite small, which this isn't. But I didn't do an in-depth review, and without seeing pictures, it's hard to compare your specimen to others. Have CC'ed Bob F and Marco, who may know better. In any event, you could deworm as a preventative, but if the fish is fine and maintaining a healthy body weight, I wouldn't worry overmuch.
Cheers, Neale.>
<<Hard to tell from the picture. I don't think this is the genital papilla.
Are you really sure this is not feces? Or a piece of protruding colon? A parasite would be another option. Marco.>>

Re: Spiny Eel Relationship Troubles (RMF, Marco -- genital papilla?)    5/29/13
Hmm, well I have had him for over two months and the size, shape, and colour have remained constant. I really doubt poop. How would a protruding colon come about? And can I do anything to fix it if that is the problem?
<No specific cure as such, but time and a fibre-rich diet (in this case, things like frozen brine shrimp) can help. See here for many cichlid examples:
You might also consider using Metronidazole and Nitrofuranace as a good general treatment for intestinal parasites like Hexamita.
Cheers, Neale.>

Re: Spiny Eel Relationship Troubles (RMF, Marco -- genital papilla?)     6/1/13
After a day of searching the corners of the web for Spiny Eel information, I've come to a near certain conclusion that the Macrognathus circumcinctus is bullying the Peacock Eel due their mating habits.
<Possible. Increasing the numbers of the smaller/weaker species may help diffuse tension, else remove.>
Several sites have stated that during mating they will chase each other violently after spinning in circles together, and mine are doing just that.
It also says that they will lay eggs in floating plants within two or three days.
<The few times Spiny Eels have been bred, yes, this is what has been observed.>
I haven't seen any eggs in my Duckweed and am assuming the two species cannot interbreed, is this correct?
<Likely so.>
Would getting more Peacock Eels still help settle them or just create more violence?
<Hard to predict. If possible, separate them. Else getting more of the picked-upon species would be the more likely solution, though adding one or two of the other species, if you had four or five of the weaker species, might encourage the bigger species to interact with themselves rather than the smaller species.>
If so how many would you recommend getting?  My Peacock Eel stopped eating for a few days (ate again today) and his/her dorsal fin is damaged. Should I just separate the two and be done with it? Your help is much appreciated.
Thanks again, Austin
<Welcome, Neale.>

Fire eel swollen and floating     – 11/20/12
Hi my name is Brenden. I have had my fire eel for about half a year now and I have never had any problems with him before. But just the other day I noticed that he was not eating. At first I was like ok maybe he's just not hungry. But then last night I noticed that he was not able to swim normal and had not control of where he was swimming. Due to this fact I took him out of the tank because I did not want him getting stuck to the filter or causing any more harm to himself but running into rocks or driftwood. I put him into a container that was ok size and I could fit a small heater in it.
I used the water from the main tank to fill it up so it would not stress him out. But getting to the point he's not moving very much anymore, there is swelling in his stomach area, he's floating, and he's losing his color.
I've have been keeping fish for about 8 years now, and this is the first time I have ran into a problem with eels that I'm not sure about. I don't know whats causing this but I may have a clue/guess.  What I think is happening is that he is having problems digesting food, which is causing the swelling or bump on him and also causing air to build up there. The only other thing i can think of that may has caused this is that my old heater was not working right, causing it to heat the tank to much and then not heating it enough, so i had to replace it, but i was not a huge change and i saw it fast enough to fix the problem, i think.  I just hope that you had give me some help/information about what may be going on and how to fix it, if its not too late.    Stuff about my tank: 60 gallons, have a nice fine sand in it, I normally keep the temperature at about 81-82 degrees Fahrenheit, I try to do water changes about twice a month or once every 2 weeks if i have the time, I took a water sample into PetSmart and the results were Ammonia:0  Nitrite:0  Nitrate: 20-40 mg/L  pH: 7.8  Alkalinity:120
mg/L  Hardness: 150 mg/L  Chlorine And Chloramine: 0   So everything is where it should be/ within the normal range    I also do add aquarium salt when doing water changes, i normally add it every other water change  Also when I went to PetSmart the lady there, I know I can trust her because I've knew her for awhile and she also keeps fire eels, said that it could be the digesting problem or maybe due to the temperature change and she told me about how people use small amount of Epsom salt to help with fish digestive problems so i added a small amount of that to the container.    If there is any of stuff that you need to know just ask me.   Also I'm going to add some pictures of my eel to show you what I'm talking about. Never mind, In the pictures I was going to show you, its too hard to see the swelling/bump.   
 Also I almost forgot that he is  also having seizure like things every now and then. I hope you can help me out and
thanks for your time.
<I'm not optimistic, but do try adding Epsom salt at 1-3 teaspoons per 5 gallons/20 litres, raising the temperature to 28-30 degrees C/82-86 F, and treating with a reliable antibacterial or antibiotic medication (ideally, a combination like Maracyn 1 and Maracyn 2 that covers both gram-positive and gram-negative bacteria for best possible chances of success). Spiny Eels are very sensitive to bacterial infections, which are often started through physical damage caused by gravel or sharp rocks. The Epsom salt will act as a laxative and muscle relaxant, both of which can help deal with some types of swelling. Generally, aim to use aquarium salt (sodium chloride) in Spiny Eel tanks at around 1-2 gram/litre, even for freshwater species like yours.
Hope this helps, Neale.>

Golden weather loach, hlth.    10/13/12
I have a golden weather loch and after pulling a dead Gourami out of my tank noticed that the back half of the loach's body has become a very dull and looks almost whitish. Also there are tons of tiny hard to see red spots on it's body. The tail fin looks as though it's collecting blood and I noticed one of my ghost shrimp nibbling on it. now I do know I had a high ammonia level recently and have been treating the tank for a week now to combat that. What is happening to my poor loach and what can I do to help him and keep my other fish safe. I have 2 peacock eels, 3 tinfoil barb's, 3 small albino barb's, and two Ruby shark in the tank. I'm hoping you can help save my fish.
<Something is very wrong with this aquarium. The combination of dead white skin (the hard flakes on the body) and the red areas are classic symptoms of bacterial infection, likely Finrot, but could equally easily be some sort of "Slime Disease" type infection (Costiasis for example). In any case, review the aquarium thoroughly: something is VERY wrong if a Weather Loach is showing this sort of damage -- they're normally very hardy. Look at the type of substrate (soft sand or gravel, nothing sharp); water quality (0 ammonia and nitrite); water temperature (not too high, 25 C or less); and no aggression or fin nipping. For just the three Tinfoil Barbs you'll need an aquarium upwards of 100 gallons, so I assume this is a very big aquarium, but if it isn't that large, plan on upgrading soon.
Furthermore, the (albino) Tiger Barbs are "nippy" if kept in groups of fewer than 6, so there's another source of problems. Ruby Sharks are aggressive, both towards each other and towards other fish they don't like, which could include the Loach (same sort of shape, habits as the Sharks).
How long have you had the Spiny Eels? They're notoriously difficult to maintain in generic community tanks. They must of course have a soft sand substrate -- never gravel -- and feeding them is a real chore if they're kept with other bottom feeders. Anyway, lots of stuff to think about.
Cheers, Neale.>
re: Golden weather loach, spiny eels as well     10/13/12

I have had the eels for about three weeks and they are happier than ever. I have a fine gravel base like what they were kept in at the fish store they came from.
<I cannot stress too strongly how important it is to use the right substrate with Macrognathus species. Anything even remotely scratchy will eventually lead to skin damage, and from that, bacterial infections. Been there, done that. Hmm… have a read:
Generally, spiny eels die prematurely because they either starve, jump out, or get skin infections.>
I have spent hours watching my tank and all of my aggressive guys chase their own kind and that's it.
<Not necessarily a good sign. If they're chasing each other, there's something amiss.>
I am planning on moving the tinfoil barb's to their own much bigger tank soon.
<Real soon…>
Currently they are small, 1-1 1/2 inches. I have a 35 gallon tank.
The largest of my creatures are the eels and they spend near 2/3 of the day buried heads out.
<What they do, and why their skins are so easily damaged.>
As far as the loach goes until today (ghost shrimp nibbling) I have never seen anything touch him short of the eels using him as a pillow. If is a fin rot, or even a mucus disease what type of treatment should be provided to help him out.
<Review Costia/Slime Disease, and treat accordingly.
Quite common. Primarily caused by a protozoan (rather like Whitespot, and often treated similarly) but bacterial infections frequently set in. Cheers, Neale.>
re: Golden weather loach    10/13/12

Thank you for the info, unfortunately the loach has passed on and now I have discovered dropsy (bloated and scales out) on one of my albinos. I'm going to be changing the floor substrate to sand as Well as do a large scale cleaning. I have done 10-15% water changes weekly and I did have a massive ammonia spike about a week ago that I believe is the root of some
of this evil. I also think I'm going to set up my spare 10 gallon for quarantine of the albinos. At this point I'm very confused as to Why it's happening but I'm pointing my finger at the ammonia spike. When I say spike I mean, on the teat it was green almost black. Very strange explosion of ammonia.  I hope I can get this under control and save these fish. I'm also in the process of setting up my 55 and 75 gallon tanks and moving my tinfoils to bigger and better.
<Sounds like you have a good plan. Don't feed the fish while ammonia isn't zero. Changing the substrate shouldn't affect biological filtration, but do take care with the filtration. Non-zero ammonia levels imply some sort of biological filtration issue: too many fish, too much food, not enough filtration (media, current). Review, and act accordingly. Upgrade the filter if needs be. Usually adding better or more filtration fixes ammonia problems. Remove carbon (if used) to make space for more biological media.
Don't add any more fish, obviously, until ammonia remains firmly at zero for some weeks. Cheers, Neale.>

Peacock eels wasting away?    9/19/12
Hi, very informative site you have here. I believe I have an issue with my peacock eels. I originally had two and just lost one. The tank is 65 gallons in a community setup.
<Mmm, hard to keep an eye on such spiny eels in large settings, get them fed amongst competing tankmates>
The smaller peacock was about 4 inches, I had him or her for about 6 months and then it refused to eat. Being that I have a few very spastic weather loaches in the tank I was worried that they were scaring him away from the cut red wigglers
<Might well need smaller food/s. See WWM re >
 I've been feeding them, so I moved him back into a 20 that I keep as a hospital tank until his demise. My other peacock eel is still in the 65, and is starting to worry me. He seems more active but a lot of his activity is spent running up and down the tank walls, he still eats and the loaches don't seem to bother him, I usually feed an appropriate sized worm every other day or so. Recently the six inch eel has began to appear skinny though, and I'm worried that something is wrong and I'm going down the same track. Water conditions are 6.8 ph, 0 ammonia, and around 10 on nitrates.
<These are okay>
I do about a 15% water change bi weekly
<I'd change at least this amount, more likely 25% every week>
and replenish any evaporated water every few days. Filtration is an Aquaclear 110 modified to give the tank some current.
<Keep the top covered to prevent these fishes leaving>
 It's got about 8 separate pieces of driftwood and many live plants. Are internal parasites common in spiny eels?
<Mmm, yes. Folks in the import part of the trade are encouraged to batch treat (via foods) w/ an anti-protozoal (usually Metronidazole) and anthelminthic (typically Praziquantel)>
 That's kind of what I'm leaning towards but could definitely be wrong. I just don't see how he can be eating and getting thinner. I haven't saw <seen> any of his waste. In this tank I also have my prized possession, a 5 inch fire eel that seems very plump and healthy(his much larger tank of the future is a work in progress but coming soon). I don't want to see him get sick. Everything else in the tank seems very healthy. What should I do?
<I might move the six inch Peacock to a smaller system... easier to observe, determine what is going on. Bob Fenner>

Cloudy eyes in my tire track eel, no data       9/5/12
I Just purchased a medium sized tire track eel about three days ago. The second day I noticed that her eyes were very cloudy then today I noticed they were puffy.
<Mmm, water quality? Often Mastacembelids have their sensitive eyes scraped in being netted, moved...>
 She is still swimming around, and she actually ate half a night crawler yesterday which surprised me because I know they are hard to get to eat.
<Actually; not this species>
I took my water to be tested at three different places and each one told me the same thing, "your water is perfect, nothing is wrong with the ammonia, nitrates, or the PH." I called the store where I got her and told them the situation and they told me, and I quote,  "that it is probably a change in PH and her eyes were burned".
<Need values, not subjective statements>
 I told them that I had my water tested three times and that nothing was wrong and they said "Well bring the water here and we will test it for you." What that tells me is that they are just trying to cover themselves, so now since I can obviously rule out help from them, I am turning to you guys for advise on what to do. She is a beautiful girl and I would hate to lose her so I'll do anything. The place I got her from kept her in a tiny ten gallon tank with two other tire track eels and a catfish of some sort, and yes they actually had them on gravel! I have a non abrasive sand in my tank so she can't hurt herself, but I know that she had some abrasions on her nose when I got her home. I am at a loss for what to do at this point, any advise you can give me will be extremely helpful and appreciated. I have attached some photo's of her below just so that you can see what she looks like.
<.... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/spinyeeldisfaqs.htm
and the linked files above. Bob Fenner>
Re: Cloudy eyes in my tire track eel    9/5/12

I have already read all of these, and none of that is happening to her. Its just her eyes.
<I see>
 I was told today that it could be a fungus
<Not likely a true fungus... much more likely a bacterial infection...>
 so I started treatment, but I'm not so sure because she has no other areas that concern me. What would you do?
<Nothing treatment wise. IF this were a wholesale/producer operation w/ many animals involved I might treat w/ soluble Oxytetracycline and a bit of aquarium salt. BobF>

Sick Peacock Eel? White on tail and head?    5/24/12
Firstly, I just wanted to say thank you for volunteering to help fellow aquarists with their problems, it is greatly appreciated.
<Thanks for the kind words.>
Here's some background: I have a 75 gallon with a built in corner overflow/and underneath wet dry filter, 80F, with 1 piece of driftwood, 2 smooth large rocks, 2-4" of pool filter sand substrate, and live Anubias, wisteria, java fern, recently added Vallisneria, and just added yesterday, Salvinia minima. Current stock is 1 ~5-6" peacock eel, 2 ~4" Senegal bichirs, and 1 ~4" African Brown Knife, 1 mystery snail, and various other snails. Water change regime is 30% every 3-4 days, and they are all being fed frozen bloodworms, frozen Mysis shrimp, and frozen brine shrimp daily currently, I am looking for live blackworms and probably will try to get some small earthworms as well, since I know bloodworms aren't the best foods.
<All sounds good.>
I got my ~5-6" peacock eel probably 3 weeks ago or so (I got him from PetSmart, in a tank that had gravel, which now I know was bad right from the get go),
<Can be bad, yes. Once their skin is damaged, bacterial infections are very common.>
and right from the beginning he has had odd behavior. (I intended to QT him, but my QT tank sprung a leak, so into the main tank he went) The first day was normal, he spent the whole day buried with just the tip of his rostrum out, night time he would come out. Second day, he spent with his head out, night time he would be out. Third day he spent 75% swimming about happily in the open, and since then he doesn't burrow himself anymore at ALL, he is out and about 100% of the time, swimming around happily. I see him more frequently then I do my bichirs. He eats the bloodworms quite voraciously, and will nibble on the Mysis shrimp sometimes.
<All sounds good and normal.>
When I first got him, on the 3rd day I noticed that he had a small kinda clearish whitish bump underneath his chin, but I wasn't sure if it was an illness, or if it was just how their heads look (I've never had spiny eels before). I've kept an eye it, and it hasn't grew at all, however, yesterday I noticed a very small white bump on his "spine" by his tail (it's not Ich). And looking closely this morning, it looks like he has a little bit of a white/clearish layer on the side of his snout. His behavior is very normal though (well normal for him), actively swimming in the tank during the day.
<I see.>
From what I've read, I am assuming its the start of a  bacterial or fungal infection?
<Could easily be. I would treat aggressively, ideally in a quarantine tank, but if you must, in the display tank. I'd use salt/heat together as per Whitespot, and also treat with a reliable antibiotic for bacterial infections such as Finrot (Maracyn 1 and 2 for example work together very well). Other types of medications might be used, but copper and formalin MUST be avoided as Spiny Eels react to them in a very unpredictable (and often fatal) way.>
If so, what would be the best treatment given his current tankmates and the fact I have live plants? I was planning on using 2 teaspoons of aquarium or non iodized table salt per gallon of water, and that was it so far. I've used Melafix/Pimafix combo when my bronze Cory a few years ago had a severe cotton fungal infection that ate both her side fins and tail and was on half her body, and she pulled through and her fins even grew back to my surprise, so I have high praises for it, though recently have read many bad reviews on how it "killed their fish." so I am unsure. I can't afford to buy a new QT tank at the moment, so whatever treatment has to to be used to treat the display tank.
<Bob F. isn't a big fan of Melafix, and frankly, given what it is, I wouldn't use it to medicate any fish once it was sick. But yes, some people have had good results with it. Corydoras are tough animals right out of the box, so it's not impossible for them to get better even with mild medications like Melafix. If your Spiny Eel is feeding and happy, you might try the Melafix alongside the salt/heat, and give that a go for the next 2-3 days. But if the white area on the head shows any sign of expanding, I'd switch to the antibiotics. And honestly, I'd skip the Melafix myself and go straight to the antibiotics. Do also be aware of Lymphocystis, a fairly common problem among Spiny Eels. Not fatal, but unsightly, and apparently connected with environmental issues even though it's immediate cause is a virus.>
Thank you very much in advance!

Dying Spiny Eel. I'm desperate.     2/2/12
I have a Spiny Eel, about 10 inches long, approximately four years old. The day before yesterday he was fine, up and about interested in food, generally healthy. Early this afternoon, I went to my tank and he was just ghastly looking, it broke my heart. At this point in time, he's on the bottom of the tank, on his side, gasping for air (harder than you can imagine). He's lost all of his colour, and seems to be slightly swollen, and somewhat stiff. He's unable to move, occasionally, he will try to turn over if I approach the tank to check on him, but that's about it. I'm heartbroken, and there have been more than a few tears shed over my fish baby.
I've completed a 30% water change, and added aquarium salt, along with some Ammo Lock. The few harlequin Rasboras I have in with him look fine, along with my Bristlenose plecostomus (although, they're both hardy enough it would take a fair effort to kill them).
Water parameters look fine, and as I said nothing else looks sickly. The only change I can think of is the heat which has taken a turn for the worst, my tank is sitting at about 34 degrees Celsius. But, this is not uncommon with our climate, and it isn't the first time, nor the last that the tank gets that warm.
Please, any information or direction to try and fix this would be greatly appreciated. I fear it may be too late for him, and am prepared to euthanize him if necessary, but he's been a loyal fishy companion for quite some time now, I'd like to try and help him before I give up. Although, seeing him suffer just makes me cry.
Thanks, Sarah.
<Hello Sarah. Do you have gravel in this tank by any chance? Bacterial skin infections (which need treatment with antibiotics) are very common with Spiny Eels when they get scratched by the substrate. Do read here:
The high temperature may be a factor too; some of these Spiny Eels come from fast-flowing streams and dislike the low oxygen levels typical of warm water. Cheers, Neale.>
Re: Dying Spiny Eel. I'm desperate.    2/2/12

Hi Neale,
Thank you so much, for a quick response. Unfortunately my eel, Ick as he was lovingly known, died about an hour ago, shortly after writing the email.
<Ah, too bad.>
I had had him for four years, so it's quite a loss. He was an awesome, intelligent creature, I'd trained to take food from hand, always leaving his random hiding space to greet me when I came to the tank. He was very much a pet, and will be very, very missed.
I would like to know what happened to him though, so in answer to your question, yes, I did have a gravel in my tank. I realise now that was a mistake on my part, however, in the four years of having him he was never sickly and never appeared injured.
<And therein lies the problem. Spiny Eels clearly can do well in tanks with gravel. But it does seem that skin infections spread across Spiny Eels extremely quickly, and scratchy gravel is very likely one cause. Perhaps it's not so much the algae as, say, not cleaning the gravel properly one time, so that there's a little more dirt in the gravel than usually is the case. I just don't know.>
Even looking at him after he has gone, he does not appear to have any physical signs of injury or illness. As I stated, the symptoms he had were some slight swelling (although that may have been because he wasn't his usual lithe, quick moving self), a complete loss of colour, almost white, and the gasping. He was absolutely fine the day before yesterday, foraging for food in the tank, hiding in his PVC tube, poking about for attention;
and then bam, it was all over.
I Googled anything and everything to try and find a solution, scoured your sites pages, but it appears it was fast hitting, and without resolution, unfortunately. That being said, I greatly appreciate your fast response, and your site (especially that faq page on Spiny Eel Health/Disease), it was the only information I was able to find that offered any serious recommendations (as opposed to the thousands of forum pages arguing water quality or overstocking, which is fine, but in a hour of need you require solid information quickly).
<Quite so. With Spiny Eels, prevention really is the key. A soft substrate and ideally a very low salt concentration (1-2 grammes/litre) seem to be the things that minimise problems.>
Thank you again, I wish I could have saved my fish baby, but in the least I'm hoping I can find a cause, and my information help someone else when and if they should need it.
<Surely the case.>
<Cheers, Neale.>

fire eel seizure  10/31/11
Hi I have had a fire eel for 2 years now we have had a few other fish they did not survive I think we had to many the tank has only had her ( or so we call her Jeanie or Houdini ) for 3 months now water changes and all she only eats red worms from a fish store today she seized started twitch and seizing lost all her color and seemed dead I held her in the water and kept stroking her side about 14 minutes later she seemed to be coming out of it gaining color back her eyes are still cloudy for about 20 minutes she
stumble around like drunk now she seems aware of everything and swimming but not totally herself. what is going on please help Greg we just bought new worms yesterday temp is 82
<Very strange... and frightening. I would label this behavior as you have... some sort of seizure. Other than the usual "good husbandry", perhaps expanding the diet or simply supplementing it w/ the soaking in
vitamin/HUFA preparation ahead of offering, I don't know what further you could do. Have you read on WWM re Mastacembelids? Start here:
and the linked files above. Does anything in your reading "jump out" for you? Bob Fenner>
Re: fire eel seizure 11/1/11

Thank you so much Bob for replying the site was very informative happy to say I put salt in the tank last night 35 gallon tank sea salt trying to be safe about 3 tablespoons and put her old tube back in that is the only thing I can think of that has change there is wood in the bottom but not enough for her to completely hide I read on your site I believe that light can cause erratic behavior and the tank was recently put in front of a window maybe that caused it?
<May be... but I suspect something else... Perhaps the wood rotting/decomposing a bit has changed some aspect of water quality. I will say that 35 gallons is small for a larger species, specimen of spiny eel, and that they can be very sensitive to accumulation of metabolites. Best to super size their systems, have redundant filtration and be VERY regular re water changes and other maintenance>
today she came out of her tube and ate like nothing had ever happened skimming the surface and nosing us for food she is a strange one I hope her tube back in will stop what happened. what else could we offer her aside from worms she is around 9" or so.
<See where you were referred to... the FAQs, feeding...>
I will be stopping at store tomorrow to test water and pick up vitamins we tried moving her over to frozen shrimp and she refused along with the other worm places is it common for them to be picky? Greg P.S you guys are awesome
<Welcome. BobF>

Striped Peacock Eel black edge on tail   10/6.5/11
<Hi there Nigel>
I recently bought a striped peacock eel (Macrognathus aral) for my 55gal tank and though he's been doing fine so far, I grew a bit concerned about a small spot it has on the tail fin (so the actual fin connected to the end of the tail, not the one running through the length of the body). It appears he has a black/brown-ish spot at the end of his tail fin, running throughout the most of the height of the fin. In addition, his tail fin isn't completely shaped like a half circle, though the dent is only very minor.
I'm not sure it's normal for the tail fin to be completely symmetrical though.
<It is... is this spot on both sides of the tail?>
It looks a bit like a burned edge on paper (though maybe more like a smudge), that's as close as I can describe it.
I was kind of wondering if this could be fin rot.
<Not likely, no>
His other fins look completely normal. On a side note I haven't noticed it spread since I got him, it's not quite like his whole tail is getting consumed (for now at least). I didn't see any fish nipping his tail fin either. I have no experience with how fin rot is supposed to look on eels.
Besides that he's a very active eel, which I did not expect because I used to have a smaller one that kind of died unexpectedly and he was a lot more timid, spending most of his time in the cave or behind some cover. This guy swims all the time, doesn't actually really hide for longer than a few minutes and is very curious. I actually started spoon feeding him less than 2 weeks since I got him (he swims to the surface). He eats very well so I'm happy about that.
Thanks for your help, I'm just wondering if I should start getting worried or not.
Kind regards,
<Not to worry. This sounds/reads as a normal growth characteristic. Bob Fenner>
Re: Striped Peacock Eel black edge on tail, and fdg.  -- 10/07/11

<Hey Nigel>
Thanks for your amazingly fast response. I've been watching the eel for a bit. It's very hard to tell exactly if the spot is on both sides of the tail or not, he never sits still.
For now I would say it's on both sides, though on one side it does seem to be less intensive so I wouldn't exclude it simply being visible through the other side of his tail.
On a side note, he only seems to eat live bloodworms.
<Spoiled... best to try weaning on to other foods... Don't worry, this fish won't starve>
I also have frozen ones but he just bites and spits them out immediately without actually eating.
He hasn't responded to other (frozen) food at all yet (such as daphnia, Artemia and white worms/mosquito larvae), he just ignores those. It also means I am kind of forced to always feed live bloodworms, which someone told me I shouldn't feed them every day because they're very fat. Is it OK for the eel to only eat (live) bloodworms and how about the other fish?
<Not okay>
I have some fairly common fish like platys, zebra Danios, glass catfish and an angelfish...so they basically eat anything. That said I do also feed them dried food and other frozen foods occasionally so it's mostly the eel I'm trying to feed properly. How can I get him to eat frozen food and what other types of food would you recommend?
<Earthworms are best... whole if small enough, cut up if not>
Thanks a lot!
<Mmm, do read here as well: http://wetwebmedia.com/FWSubWebIndex/spinyeelfdgfaqs.htm

Mastacembelus randomly dying -- 07/02/11
Hello WMM.
In the past I have had terrible luck with my Mastacembelus sp. dying unexpectedly on me. My first occurrence was my beloved Mastacembelus cryptacanthus. We had him in the LFS tanks for months and he was doing fine and then I brought him home and he got used to the tank quickly and after 3-4 months died unexpectedly with no warning signs at all. My tank had no ammonia or nitrate and nitrates were <10. My next experience with these fish was with some Mastacembelus sp. "Starry Night Eel" that we had at our wholesaler at work. All of the fish in the tank had the same shape as M. cryptacanthus and a few had the same pattern too. Most of them did have a more spotted pattern though. I ended up purchasing four. Two suddenly died in a few weeks, one squeezed through a hole in the new aquarium and one ended up surviving. Again, none of these fish posed any problems and the water parameters were even better in this aquarium with nitrates at 5ppm.
Now I saw this beautiful Mastacembelus brichardi but I don't want to spend a large amount of money on a fish that could very well die unexpectedly from unknown conditions. It may also help if I mention these fish are from Africa and not farms and many of our Reedfish from Africa seem to come in even worse.
Do you have any ideas on what this could be? I am completely baffled as to what this could be.
Thanks! Tyler from Buffalo, NY.
<Tyler, there are a bunch of issues with Spiny Eels. One is that they're difficult to feed. While you may be offering the required earthworms and river shrimps, the exporter, wholesaler, and retailer may not. So your specimens could be severely underweight once you buy them. Buying specimens as soon as they arrive at your local retailer, quarantining new specimens until they feed well, and then introducing them to tanks where they can feed comfortably (no loaches, no catfish!) will help here. Secondly, bacterial (and perhaps external protozoan) infections are a problem with Spiny Eels across the board. Typical symptoms including wasting as well as bloody sores and/or white slime on the body. I'm not aware of any established protocol for dealing with this in terms of antibiotics, but you certainly want to avoid specimens with any sign of physical damage and also to ensure your aquarium has nothing liable to scratch their fins (no sharp rocks, no gravel, etc.). Design the tank specifically for these easily-damaged fish -- smooth silica sand (pool filter sand in the US), waterworn bogwood, round cobblestones, no openings at the top of the tank, floating plants to inhibit jumping. Aquarium cleanliness needs to be very high, so besides good water quality you want lots of water movement at all levels, and you need to ensure that detritus at the bottom is regularly removed. The addition of a small amount of salt, 1-2 g per litres, does appear to be very beneficial for Spiny Eels, particularly in the first few months, though some writers, e.g., Baensch Aquarium Atlas, suggest it's added all the time. I should report that once settled I've never found Spiny Eels particularly delicate, but those were Southeast Asian species, and it may well be that the established exporters from Asia and the Rift Valley lakes are better at distributing these fish than the exporters from Central Africa. Do also note that the Blind Spiny Eel, Mastacembelus brichardi, is a fast-water species, so you will need to create a tank with very high water flow as well as caves and cobblestones. Cheers, Neale.>
Re: Mastacembelus randomly dying   7/4.5/11

Thanks for the info Neale, you guys at WWM never let me down!
<Glad to help, and thanks for the kind words! Cheers, Neale.>

tire-track eel swimming abnormally -- 05/07/11
I have a sick tire-track eel and I am at a loss as to what I should do. I have a 500 lt. "paludarium" setting that is 3/4 full of water, with carnivorous plants above water level and lots of floating plants. Water parameters seem fine: ammonia 0 ppm, nitrate <10 ppm, pH 6.0 (last checked.)
Water temperature is 28 C. Tankmates are: an 14'' Arowana, two BGKs, two Senegal bichirs, and several smaller spiny eels. Here are some pictures, though I haven't updated in a while.
The tire-track is approx. 12'' long, and has been a resident of our tank for months. I've been feeding it on a diet of anchovy pieces,
<Pieces? This type/family of fishes can be a bit too fatty... Please read here re spiny eel nutrition:
with the occasional shrimp. I always remove the fishbone carefully before feeding.
The tire-track eel was a voracious eater and quadrupled in size since I got him. (I got him from a pet store where it had been starving for a month.)
It was a very timid creature, always nestling inside the huge sea urchin shells I bought for him. A week ago, however, something went wrong. The eel left his urchin shell and started wandering around. We considered that happy news at first, but two days later I observed that the eel was swimming abnormally, often turning upside down
<A very bad sign>
and staying motionless for moments. I immediately did a 40% water change and tested the water, but everything was normal.
<... for what you have tests for>
I have done two more smaller water changes since, and I've cut down feeding just in case. A week has passed and nothing has changed. The eel is still active, swimming to every corner of the tank, sometimes upside down and sometimes normally. I also find it contorted in an S-shape from time to time. He stays motionless in that position. There is no visible bloating.
He has not accepted any food since the symptoms began.
<Try other foods>
I considered using medication for internal parasites, but I read that they can kill your fish, so I'm waiting your advice on that.
<I too would not treat for parasites. The problem here is likely environmental. "Something" is amiss chemically, physically here. Perhaps one of the plants of the paludarium is poisoning the water...>
Your website is a
genuine encyclopedia. I've read the FAQ section on spiny eels but couldn't find anything that applies to my case, so I'm bothering you with this e-mail. All help appreciated!
<I would utilize a good deal of high quality (activated) carbon, maybe the product PolyFilter in the water flow path... keep doing large water changes, NOT use Anchovy OR shrimp in this fish's diet. IF the symptoms and non-feeding continue more than another week or two, I'd be moving the tire track, possibly all the fishes here. Bob Fenner>

bubbles on eyes 3/1/11
Hi and Good morning. I have done some searches and can't find ideas on what may have happened to my black spotted eel.
<I see a Mastacembelid w/ an opaque eye...>
I've had him for many months and he's been thriving and growing rapidly.
He's probably 13 inches long. He's the king of the tank. However last night when I was feeding my fish, I noticed my eel wasn't coming to the surface to get his food (he eats from my hands). I found him and he had bubbles formed over his eyes. He also looks to have some swelling around his mouth. He was fine the day before. Do you know what may have caused this and how to treat it?
<Not given the paucity of information here... need to know water chemistry, the other livestock, set-up, maintenance... Likely a physical injury though>
I don't have any fish with him that could possibly harm him besides maybe a match against a Pictus catfish. His tank mates are a Ropefish, an angel fish, a parrot cichlid, a diamond tetra, 3 silver dollars, a rainbow fish, a farawello catfish, and of course the Pictus.
<Mmm... not a good mix water quality wise>
Please let me know your thoughts. Attached is a photo. Thanks for all your time!
<Do read re the ranges, needs of the species you list... measure water parameters and report back. Bob Fenner>

Re: bubbles on eyes 3/1/11
Thanks for responding so quickly....
Ok, water chemistry:
Ammonia 0
nitrite 0
ph 8.3 (always been this high, fish are used to it)
<Ah, no... go back, read our prev. corr... Check out the needs of your livestock. B>
livestock...Ropefish, an angel fish (3" from tip to tip), a parrot cichlid (young 50 cent piece body), a diamond tetra, 3 silver dollars (largest being about 3 " around) , a rainbow fish, a farawello catfish, and of course the Pictus about 4" long. I know it's a strange mix but they all get along.
Well sometimes the diamond tetra chases the silver dollars around which is funny b/c she's half their size.
We do a 50% water change once a week with the last change being Sunday. I add freshwater salt (1 tbls per 5 gallons) and stress coat to the water.
The water is well water.
I hope I answered everything.
I know from the first photo his eyes just look clouded but they are actually
swelled up bubbles. They are like half a bubble on each eye and his lips look swelled too. I'm attaching more photos so hopefully you can make out the bubbles. Should I treat him with meds? If so which kind is safe for eels? I have Melafix???
This is my favorite fish, so please help. Thanks for all your time!
 <... keep reading>

new Fire eel, Neale's go  10/25/10
Hey guys, I just got in a new 7inch fire eel and it looks ok, but I noticed that while it was in the fish store they had it in gravel and any time I would go look at it b 4 taking it home it would be buried in their regular size round gravel. In my tank I've got white and back sand, and sum plants and stuff for him to hide and feel more comfortable. my question is, is there a reason he is not burying himself in the sand but keep chilling at the top of the water in the plants? I've read that ppl talk about this but they say their eel is on its side or upside down. mine is not its just up there not really doing n e thing. don't get me wrong at night he moves around and stuff. but .. how come no burrowing?!? it that ok or what?
thanks for the help guys at WWM :)
Bless! Brad
<Hello Brad. If you have plants at the top of the tank, especially floating plants, it is very normal for Spiny Eels to tangle themselves up in those plants. In fact spawning seems to take place in floating plants. So if your chap otherwise looks healthy, and better yet, is eating, I wouldn't worry about it. Cheers, Neale.>
new Fire eel, BobF's turn  10/25/10
Hey guys, I just got in a new 7inch fire eel and it looks ok, but I noticed that while it was in the fish store they had it in gravel and any time I would go look at it b 4
<Please, no "net speak">
taking it home it would be buried in their regular size round gravel.
<... please read here:
and the linked files above re Mastacembelids>
A/the choice of substrates with spiny eels is crucially important>
In my tank I've got white and back sand, and sum plants and stuff for him to hide and feel more comfortable. my question is, is there a reason he is not burying himself in the sand but keep chilling at the top of the water in the plants?
<Likely this gravel is too coarse, sharp... painful to its skin>
I've read that ppl talk about this but they say their eel is on its side or upside down. mine is not its just up there not really doing n e thing. don't get me wrong at night he moves around and stuff. but .. how come no
burrowing?!? it that ok or what? thanks for the help guys at WWM :)
Bless! ..Brad
<Brad, in future, please run your missals through a spelling/grammar checking ahead of sending.
Bob Fenner>
Re: Sick Eel with White Patches

Thanks, unfortunately the eel did not recover and had to be removed.
<Sorry to hear this.>
This was an extremely fast-moving infection, especially for such a large fish (3'). From zero symptoms to dead in 3-4 days.
<Indeed, very fast.>
Nitrates were tested at 30 or less (per color scale) every month or so, but it is a 400 gallon tank with only 3 fish and 2 (now 1) eels so the biological load is light. Has about 250 lbs of live rock in the main tank and a bioball filtration system in the sump. Water changes 40 gallons every 10 days. I don't have a PH score right now but most likely it is fine given this maintenance.
<Yes, sounds OK.>
Both eels came from LFS about 6 months ago that was trying to get rid of them due to lack of demand. Neither one can be described as aggressive eaters in the sense they will dash out and grab at food, have to put the food on a stick and put it near their mouth before another fish grabs it. So they got plenty food but maybe not the strongest to start. Maybe that is why the LFS was getting rid of them. I will watch the remaining one and continue to monitor tank conditions and consider the hospital tank at the first sign of trouble.
<I'd also add vitamins to its food regularly (at least once a week) to replace anything lost due to freezing and thawing processes. Cheers, Marco.>

Fire Eel Sick  10/21/10
I have a Fire Eel whom I have had for a couple months now.
<Nice fish.>
He just recently started to have these white spots appear on him and is losing the color in his rostrum.
<Oh dear.>
They appear to be discoloration and are not on the outside of his skin. I'm pretty sure that it is not Ich but I'm not sure what it is.
<Fire question. Do you have gravel or sand? Gravel damages the skin of Spiny Eels, and since they use their nose to dig into the substrate, the nose is often the first part of their body to get damaged. Small specimens are particularly at risk, and while large spiny eels -- upwards of 45 cm/18 inches -- might be okay with smooth, fine gravel, I personally would never, ever keep a spiny eel in a tank with gravel. It's just too risky, and the evidence gravel damages them is overwhelming.>
He recently fell on the carpet and was out of the water for a short period of time.
<Exposure to air is in itself not a disaster, provided the fish is quickly returned to the tank.>
I got him back in the aquarium quickly, but right after that is when he started to show signs of an illness.
<Yes, likely damage to the skin. As with gravel, drying can cause damage to the skin, and the longer the fish is exposed to air, the more serious the risk of damage. Spiny eels are incredibly sensitive to this sort of thing, and once the skin is damaged, opportunistic bacterial infections aren't far away.>
The tank is kept at 80 degrees Fahrenheit with a small amount of aquarium salt.
<How much? I'd add at least 2-3 grammes/litre, just as if treating Ick.
This won't stress the other fish, and will be a preemptive strike against Ick.>
Nitrates are at 10 ppm, Nitrites at 0 ppm, hardness is 75 ppm (soft), 0 chlorine, low alkalinity, and 6.8 pH. 45 gallon tank with a 20 gallon sump (I know I will need to get a larger tank once he grows).
<I'll say! These fish are gigantic. Average specimens in aquaria are about 75 cm/30 inches.>
Tankmates include a Featherfin Synodontis and an Ornate Bichir both of which are small.
<Okay. Potentially good tankmates, though I'd tend to favour salt-tolerant species simply because spiny eels do better when salt is used regularly.
Siamese Tigerfish and some of the cichlids make good companions because of this.>
Tank has lots of hiding spots. Feeding the Eel and Bichir earthworms and the Featherfin sinking carnivore tabs. Could the disease be velvet, or something else entirely? If so, what should I do? Thanks in advance.
<Unfortunately, my guess would be a bacterial infection, and I'd treat with an antibiotic. Spiny eels are finicky fish and difficult to maintain if you don't do EVERYTHING right. Do be sure to read everything you can about these fish, and act accordingly. Both Marco L. and myself have kept these fish and written articles about their needs:
Cheers, Neale.>
Re: Fire Eel Sick - 10/21/10

Thanks for the quick reply,
<No problem.>
I have sand in the tank so it shouldn't scratch him when he buries himself.
<The sand is smooth, right? Not sharp? Bear in mind that some sands, for example Tahitian Moon Sand, are abrasive, and these must not be used with Spiny Eels.>
He was only out of the water for thirty seconds max so hopefully his skin didn't dry out to much.
I have put in two tablespoons of salt in the tank already so I will add some more.
<As per dosage.>
What medications would you recommend to treat him with?
<Antibiotics are safe, but otherwise avoid medications where possible, especially copper and formalin.>
Should I start a hospital tank to treat him?
<Would leave him in situ.>
Thanks again.
<Cheers, Neale.>
Re: Fire Eel Sick
Thank you very much!
I have done as you said and will go out to get some antibiotics today. The sand is smooth so it will not hurt him. I deeply appreciate the help.
Best Regards,
<Glad to help Ben. Good luck! Cheers, Neale.>

Fire eel question (Bob, some questions about your Spiny Eel piece)<<Ok>>    10/19/10
Hey Guys,
I was at my LFS and came across some amazing Fire Eels.
<Beautiful fish, though very difficult to keep for a variety of reasons.>
A fish that I had only ever seen in videos on YouTube. I knew right then that I wanted to bring one of them home with me. I've got a 8'x2'x2' tank, crushed coral substrate and smooth black river rocks making caves with 6, 5" Fronts, 2 4" blue dolphins, 1 9" black Arowana and 2 4" Altolamprologus.
<Here's the deal. Hard water isn't a major problem as such, but crushed coral will probably raise the hardness and pH well above the comfort zone for these essentially soft water fish. They really need something in the range 5-20 degrees dH, pH 6-8. Yes, there are spiny eels in both Lakes Malawi and Tanganyika, but not Fire Eels! Any of the Malawian or Tanganyikan species would get along fine with all of these fish, except the Arowana, who has no business being in a hard water community at all, and in
any case, will soon start seeing the smaller fish as food.>
<<And crushed coral is a very poor/unsuitable substrate for keeping Mastacembelids>>
In the research that I've been doing over the weekend I think the Fire Eel would do ok in my tank with the fish I have now.
<Not quite. The tank is big enough, and Fire Eels have certainly been kept with Arowanas, particularly the relatively peaceful South American Arowanas. On the other hand, the water chemistry required by Malawian and Tanganyikan cichlids is far towards the hard/alkaline end of what Arowanas and Southeast Asian spiny eels appreciate. In short, not a textbook combination of species.>
Question 1) will it?
<Does depend on water chemistry, about which you've said nothing. Also, the substrate needs to completely smooth, I'd recommend smooth silica sand, or failing that, very fine, rounded gravel. Crushed coral and/or coral sand is right out. Any rocks need to be smoother than smooth, baby's bottom smooth.
Anything with any sharp or even rough edges is putting your Fire Eel at severe risk of death. The danger is, as I hope you understand, damage to the skin. Once scratched, these fish are astonishingly prone to bacterial infections. They react badly to copper and formalin, and even antibiotics have a poor track record when it comes to treating sick fish. Obviously, this predisposition to disease is another reason why "feeder fish" should never be used, and diet has to be very carefully controlled to include lots of thiaminase-rich foodstuffs. Earthworms are the single best food around for spiny eels.>
the eels at the store are about 6" to 7".
I have a cover on the tank now but are they really that adapt at escaping?
<Yes. If they can escape, they will. DO NOT delude yourself otherwise!>
Those are the basic questions I have, my main concern would be the small white blob spot on the tail of one of the eels. From what I've read it could be Ick, as the eels had just got to the shop a day before, and if so adding salt and increasing the temp in the tank would help kill the bacteria?
<Salt/heat will treat Whitespot just fine. As for bacteria, there is some argument, e.g., in Baensch vol. 1, that maintaining slightly brackish conditions improves the health of Fire Eels and indeed Spiny Eels
generally. I kept my Tyre-Track Eel in brackish water for several years alongside mollies, Rainbowfish and other salt-tolerant tankmates. Baensch recommends 1-2 teaspoons per 2.5 US gallons, or about 6-12 grammes per 10 litres. This is a very low dosage, far below what is officially brackish water and not enough to stress freshwater fish in most cases, but do observe your other fish and see how they react.>
However in one of the articles I found on your site,
Bob Fenner said "Should any of the spiny eels in the system exhibit red areas, particularly near fin origins, or white, blotchy markings, leave all of them. They are likely to be soon dead."
<Bob is on the money here. Fire Eels and spiny eels generally are extremely prone to these bacterial infections, and if the retailer has done stupid things like keeping them in tanks with gravel, or has fed them feeder fish, then all bets are off. You might take a gamble on a healthy specimen alongside one or more sickly ones, but for the best chance, pick a healthy fish from a batch of healthy fish.>
What is this 'white blotchy marking' on the tail?
<It's essentially Finrot, some sort of Pseudomonas or Aeromonas infection of the skin. You're looking for patches of white mucous initially, followed by reddening, dead white skin, cloudiness of the eyes, and then death as the disease progresses.>
is it really that bad,
is there nothing I can do about it
<Antibiotics may help with minor infections, and maintenance in slightly salted water is probably a plus. But once a spiny eel gets really sick, they are notoriously difficult to treat.>
so I can bring one home and nurse it back to health, or should I just stick to admiring these fish on YouTube Videos? Thanks for your help guys! :)
<Do be sure to read everything you can about these fish, and act accordingly. Both Marco L. and myself have kept these fish and written articles about their needs:
The bigger species of Mastacembelus are perhaps less sensitive to substrate type than the smaller Macrognathus, but apart from the rock-dwelling Malawian and Tanganyikan species, all spiny eels should be kept in environments as free from sharp edges and rough surfaces as possible.>
Bless! Brad
<Cheers, Neale.>

fire eel. Mastacembelid sys., hlth.  6/10/2010
Hello, I found your site doing a search on fire eels.
<A lovely fish.>
I bought one a few weeks ago and I put him in my tank with gravel. I noticed he was digging so I took all of the gravel out of the tank and made my tank suitable for fire eels. I now see white scrapes on his body with a couple of white spots.
<Yes, this is the classic problem. Smooth, round gravel is just about okay if their are lots of bogwood roots and caves where the Fire Eel can hide.
But if he feels the least vulnerable, he will try to dig, and when they dig, they get scratched.>
He is eating fine and is quite happy.
I am concerned about the white scrapes/spots. Do I need to medicate or will the scrapes/spots go away?
<I wouldn't medicate directly, but a small amount of aquarium salt can help. Baensch recommends 1-2 teaspoons per 2.5 gallons, which isn't very much. For whatever reason, small amounts of salt seem to minimise the risk
of secondary infections where spiny eels are concerned. Note that they aren't brackish water fish, so marine salt isn't what you want here; marine salt mix would raise the pH and hardness, not just the salinity. Just plain vanilla aquarium/tonic salt, sodium chloride.>
I have done so much research and don't know if I should medicate. The spots have been on my eel for about 3 days. Your help would be much appreciated!
Best Regards, Jennifer
<A cheap, easy fix here Jennifer, so be of good cheer! In clean, clear water he should heal just fine. Don't forget to keep him nice and warm though; these eels are hothouse flowers, and need to be kept around 25-28 C/77-82 F. If they're chilled, their immune systems will weaken. Cheers, Neale.>
re: fire eel 6/11/2010

Thanks Neale for the quick reply!
<No problem.>
The tank is at the right temperature and I did add some aquarium salt this morning.
I will keep a good eye on him and if I see things worsen, what kind of medication would be best for my newest family member?
<As stated, salt is the best tool for prevention as well as treating things like Ick. Otherwise antibiotics, possibly methylene blue. Avoid copper, formalin and malachite green.>
He is an awesome fish and we have become quite attached to him.
<Indeed he is.>
I will do what ever it takes not to lose this guy.
<Quite right!>
Thanks Again! Jennifer
<Cheers, Neale.>

Escaped zigzag eel 5/26/2010
Hello All.
I have a major emergence here. Two days ago my zigzag ell spent about 20 minutes crawling around on the carpet.
<Ah yes, a favourite hobby of spiny eels generally.>
He was still alive when I found him, but was covered in cat hair and dust.
I had a pail of aquarium water close so I picked him up, put him in and as gentle as possible wiped it off.
He is now in a 10 gal. hospital tank, but not in very good shape.
<Indeed not.>
The tank has an eclipse filter-water at 81deg,-air stone running. He is 3yrs old, about 7ins long. The main problem is approximately 2in. of skin is missing on his right side from the tail forward.
<I see.>
He just lays in one spot on his left side and very seldom moves. Is there anything I can do for this injury or should I put him out of his pain?
<I'd be doing two, maybe three, things. The two things I'd definitely do would be to add a little aquarium salt to the water, 3-4 grammes per litre is ample. That will reduce some of the salt loss through the damaged tissue. The second thing I'd do is add a product like Stress Coat to the water. Again, this helps deal with damaged mucus and skin, reducing the risk of subsequent stress and infection. The third, optional, thing would be to add a broad spectrum antibiotic. That would minimise the risk of Finrot and speed up healing. In the meantime, find out how the spiny eel escaped: these fish are notoriously good at getting out of aquaria through small gaps in the hood. Floating plants help inhibit this behaviour, but even so, you need to make sure the hood is secure. Hang-on-the-back filters
are completely unsuitable for spiny eels, since by definition they need a whopping great gap at the back of the hood. The best filters are internal canister filters, since these require only a small hole for the power cord, and you can further plug that hole with filter floss if needs be.>
Thank you for any advice
Dave H.
<Cheers, Neale.>

Fire eel problems...hlth., English   -- 04/22/10
ill try to make this short
<Complete sentences and proper spellings would be nicer.>
fire eel
17inch and fat
purchased about a week ago ate first day earth worms second day ate fine third day ate fine then began to lay on side breathing heavy then next day was fine fed again
<Hmm... Mastacembelus species are notoriously sensitive to bacterial infections, dips in water quality, waterborne toxins including copper and most medications, and generally anything that might cause stress. It's absolutely crucial to react to even the slightest signs of ill health quickly. That means not assuming things will get better by themselves, but immediately trying to establish the possible causes of any problems like rapid or laboured gill movements. The obvious things to check are sudden pH changes, non-zero nitrite and ammonia levels, and dips in oxygen content, e.g., because the filter is running slowly.>
now this time he was on his side breathing heavy then an hour later he would be right side up but still breathing heavy this has been going on for 2 days now of constant breathing heavy and on being on his side off and on
he keeps mouth open
no sign of visual damage
fins look fine
no white film around body
no fungus
looks healthy body wise
could this be parasite infection?
<Probably not.>
from worms?
<Not earthworms, no.>
I feed all other fish in tank worms though and there fine.
<Generally earthworms are a good staple for Spiny Eels generally.>
thing I am doing to try to help turn all lights off incase he just stressed?
<Certainly darkness reduces stress, but in and of itself it won't cure problems.>
dont no from what he was fine when I put him in the tank almost a week ago <"A week is a long time in politics...">
running two air stones raise temp to 83 degrees
<A bit warm, to be honest, and if oxygen content is an issue, warming up the water will only make things worse. An ideal temperature would be around 25-26 C, 77-79 F.>
my tank
135 gallons
stock list:
1 Oscar
2 Severums
1 Pleco
fire eel (fish in question)
AC 110
two air stones
bare bottom tank
<Something Spiny Eels hate; if you can, use *smooth* silica sand so they can burrow freely. Avoid gravel. But absolutely avoid bright light/reflections from underneath. Install floating plants, e.g., Indian Fern, for shade. The use of floating plants doubles the lifespan of Spiny Eels simply by inhibiting their tendency to jump out of aquaria. If I sold fish, I'd given away a clump of Indian Fern with every Eel sold!>
PVC for the eel only
<What about the catfish? Spiny Eels are easily damaged by aggressive Loricariidae. It isn't so much the size of the catfish, but their ability to cause superficial wounds with their spiny bodies. Once damaged, infections set in super fast.>
my water test results are as followed
please help
<Mastacembelus erythrotaenia is a notoriously difficult fish to maintain.
It is a highly sensitive fish, and should not be exposed to sudden changes in pH or hardness. Water quality needs to be excellent, and that includes taking precautions against chloramine, copper and ammonia in your tap water. Water chemistry needs to be middling, not too soft and not too hard; 10-15 degrees dH, around pH 7 is ideal. The use of a little tonic salt is often essential. Baensch recommends 1-2 teaspoons per 2.5 US gallons, something I'd agree with from my experience with the similar species Mastacembelus armatus. It is important to never use "feeder fish" around these Spiny Eels; they'll eat them readily enough, but the risk of simply exposing them to bacterial infections, let alone parasites, is just too great. Since this is a new specimen, the possibility of either Velvet or Ick is something to consider; Velvet especially tends to go for the gills before the body, and Spiny Eels are prone to ciliate parasites even under the best of conditions. Again, the use of salt will help here. Cheers, Neale.>
Re: fire eel problems -- 04/22/10
ok were do you recommend going from here with the info I gave you?
<Do read:
should I use a combo of Melafix and pima fix?
<Minimal value.>
add salt
<As stated.>
bring temp down a bit?
<Unless treating for Whitespot, in which case the combination of heat and salt. Cheers, Neale.>

HELP!! Mastacembelus erythrotaenia   1/16/10
Help for my 25'' fire eel. I had it now for a year and last night I noticed he has a few white spots on it's tail and it's fins but until last night he was eating well. What can I do?
<A few white spots... on the fins and tail? I'd keep a watch out, but not add anything here... Possibly raise temperature... along with aeration, circulation, to the mid 80's F. if you really think this might be a Protozoan>
I just performed a 30% water change with RO water and I added two teaspoon of salt. All my parameters are ok. ph 7.2 nitrates 0. Basically my parameters are the same as they were one year ago and I perform tests every 2 weeks.
Let me know please I don't want to loose him!!!
<Or lose it... What would Doug Adams likely write? "Don't panic!" This may be "nothing". Treatment could definitely be worse.
Bob Fenner>

Re: HELP!! Mastacembelus erythrotaenia 1/16/10
> Hi Bob,
> In my experience, spiny eels are very prone to bacterial infections, especially in tanks with gravel rather than sand. Once sick, they seem rarely to recover.
> Baensch recommends 1-2 (presumably level) teaspoons per 2.5 (presumably US) gallons to ward against ciliate infections. Would certainly advise being a little more aggressive than "wait and see" with these fish -- adding salt would be sensible. Having an antibiotic to hand would be wise if the infection is a bacterial one rather than, say, Ick.
> Cheers, Neale
<If you can find the querior's addy, do feel free to send along your input. IMExperience, "some" spottiness is not nearly as dangerous, and likely transient with spiny eels than "most" treatments. B>
RE: HELP!! Mastacembelus erythrotaenia
Will keep an eye on him and watch if he eats sufficiently and I will let you know
Thank you very much for your prompt reply!
<There is a message from a fellow crewmember I'm prompting...>
RE: HELP!! Mastacembelus erythrotaenia
Will keep an eye on him and watch if he eats sufficiently and I will let you know
Thank you very much for your prompt reply!
<Hello Antonis. With Bob's permission, I'm going to offer a second opinion here. In my experience, spiny eels are very prone to bacterial infections, especially in tanks with gravel rather than sand. Gravel scratches the skin, and this allows secondary infections comparable to Finrot (and very likely Aeromonas, Pseudomonas spp. infections). Once sick, they rarely seem to recover even if treated with antibacterials. Quite likely organic dyes, formalin and especially copper are toxic to them, so these kill the Spiny Eels even if viable treatments for the bacteria. Furthermore, Baensch recommends 1-2 (presumably level) teaspoons salt per 2.5 (presumably US) gallons to ward against ciliate infections (Ick, Velvet, etc.). I would advise being a little more aggressive than "wait and see" with these fish. Having an antibiotic (rather than a copper, formalin or organic dye antibacterial) to hand would be wise if the infection is a bacterial one rather than a ciliate one. If you suspect a ciliate infection, add salt; Spiny Eels are very salt tolerant, so there's little risk involved.
Understand the differences between them, and act accordingly. And do, of course, review any potential problems with the tank -- water quality, abrasive gravel/rocks, aggressive tankmates, etc. Cheers, Neale>
Re: HELP!! Mastacembelus erythrotaenia   1/17/10

I was actually looking for your reply Neale!
My gravel is rounded so no risk there and I only have Anubias and 2 ghost knives in my tank so no danger there my tank is 500ltr so how many spoons of salt I shall put.
<<The Knifefishes will NOT like the salt addn. RMF>>
<The standard recommendation for treating Ick with salt and heat is to add 2 to 3 teaspoons of salt per US gallon, while raising the temperature to 82-86 F (28-30 C). It's best to use tonic salt rather than marine salt mix so that you don't alter the pH and hardness. 500 litres is nominally 132 US gallons, but by the time you allow for gravel, rocks and such, you can usually knock 10% of the volume, so your tank probably holds more like 120 US gallons.>
<<And this much salt added may well destroy or at least send your nitrifying microbes into a metabolic check. RMF>>
As for medications I have JBL's Punktol (especially for white spot) that I know from experience that is very good but I don't know haw harmful it can be to spiny eels.
<I am not overly familiar with this medication, but it is based on malachite green, an organic dye, rather than copper or formalin. Organic dyes tend to irritate sensitive fish, so I'd recommend against using this medication. Plain salt/heat is best for Ick or Velvet, potentially raising the salinity up to SG 1.003 (about 6 grammes per litre) if needs be.
Antibiotics would be preferable for bacterial infections.>
What do you recommend. I already raised the temp to 29.5 just in case and I'll try to feed him earthworms tomorrow because he hasn't eaten since yesterday :o(
<Wouldn't try feeding until you've identified the problem and started the treatment. Cheers, Neale.>

Ellipsifer eel question, hlth.  -- 09/22/09
I have had two ellipsifer eels for about three years now.
<Mastacembelus ellipsifer, put into the genus Aethiomastacembelus by some.>
One died recently, she was the larger female prone to what I thought was egg binding...her middle would get very fat and her vent would protrude a lot. Epsom salts would help to clear that up. This happened on and off for 8 months maybe.
<Maybe this was not caused by egg binding or solved by Epsom salt.>
A few months ago, the larger female just stopped eating. Nothing visibly wrong with her. Same diet, same tank, no new tank mates. After a long period of not eating, all other tank occupants remained fine, except my second female ellipsifer. Her appetite started to wane. She never got a bloated belly though. I decided to medicate the tank with metro. Didn't work. The larger eel died a week or so later, the smaller of the two eels stopped eating completely and hasn't eaten for about 2 weeks now. She doesn't look sick in any way, just won't eat. She normally eats frozen mysis shrimp. Doesn't want it. Offered her frozen bloodworms, doesn't want it. Tried soaking the food in garlic, not interested. All other tank occupants are fine, and I've since stopped using metro as it didn't seem to be helping and I don't really know what's wrong anyway. Not sure what to do at this point.
<My first approach would be to check the water parameters of the tank. These eels are from lake Tanganyika (they are endemic and occur in nowhere else in nature) and need corresponding water (alkaline, very hard, nitrates below 20 ppm) to stay healthy. See here for details: http://www.wetwebmedia.com/ca/Volume_5/RV_Cichlids.htm . You can try small earthworms/nightcrawlers from a toxin free garden or live bloodworms. Most spiny eels love both. Livebearer fry would be another alternative. Mysis shrimp should not be the only food item, but rather compose a small percentage of your eels' diet. If you are using frozen foods you may want to feed vitamins on a weekly basis to help the immune system.>
She is in a hospital tank. What medication could I try on her that would be safe for an ellipsifer?
<Since we cannot tell from the symptoms of not eating and dying what your eel has, I'd aim for an improved environment if necessary and try different food items (live worms of any kind). With regard to a possible disease I can just guess that there might be some internal bacterial infection. Spiny eels can be treated with the common antibiotics like Maracyn, but as noted above I believe this might rather be environmentally caused or deficiency disease related. For general information on the family also see these three links: http://www.wetwebmedia.com/FWsubwebindex/matacembelids.htm  http://www.wetwebmedia.com/FWsubwebindex/spinyeelsmonk.htm  http://www.wetwebmedia.com/ca/volume_4/V4I3/Spiny_Eels/Spiny%20Eels.htm .>
Thanks, Kelly.
<Good luck. Marco.>

Mastacembelus erythrotaenia; diet; health - 7/16/09
I am starting to get really worried about my fire eel. He has always loved prawns as his main diet, rarely touching anything else.
<Prawns contain a lot of thiaminase; over time, this causes Vitamin B1 deficiency. Use prawns only once or twice per week, and handsomely outweigh them with foods that don't contain thiaminase, such as earthworms.
Water conditions are perfect, I change at least 25% once a week and he has always been active and seemed happy, never tried to escape or have any problem with tank mates. 6 days ago he stopped eating and wont eat anything I try to temp him with (blood worm, river shrimp, muscle, prawn).
<Oh dear. Earthworms are, without fail, the things Spiny Eels enjoy. So try them. Offer them at night, or else using long forceps, so other fish can't steal them.>
I noticed a couple of days ago a small white rotten looking patch at the end of his tail and have treated the tank with ESHA 2000. He has become a bit more active than he was initially ( when I first noticed he wouldn't eat, he stopped coming out of his tunnel) but is acting strange and still wont eat. He used to investigate everything, now he is just sitting on the bottom, or as I saw earlier with his head at the top and balancing on his tail at the bottom (not for O2 as there are 2 air stones in the tank with more than enough O2).
<Spiny Eels are tricky fish, and if given a monotonous diet, they are prone to malnutrition and hunger strikes. There's also the fact bacterial infections seem to affect them more quickly than most other freshwater fish. You're wise to treat what might be a bacterial infection promptly; in the meantime, review the basics, and if needs be, starve the fish until it takes some other types of food.
Baensch recommends adding a little salt; 2 to 4 teaspoons per 5 gallons.
While this isn't something you'd want to do all the time, it might well be helpful in this situation as it helps detoxify nitrate and nitrite.>
He is about 35 cm long and in a 50 gal tank. I have had him about 6 months.
Please give me some advice.
<Cheers, Neale.>
Re: Mastacembelus erythrotaenia; diet; health - 7/16/09

thanks for your quick response. I will try earthworms to temp him back to eating.
With regards to salt, I had heard that its not advised to put any salt in with Corydoras. I have a sailfin Pleco, 2 gold nugget Plecos, 6 clown loaches, 7 bronze Corydoras, a Firemouth cichlid, 2 silver sharks, a pair of dwarf Gourami and a Siamese fighter. Would the salt still be a good option as everyone else is happy and healthy?
<This dose of salt is harmless as a short-term therapy. In any event, Mastacembelus erythrotaenia shouldn't be kept with most of these fishes.
The Betta is live food, as is the Dwarf Gourami. Corydoras are choking hazards. Silver Sharks and Clown Loaches can be good companions, given sufficient space and assuming they're big enough not to be eaten.
Mastacembelus erythrotaenia is a darn big fish when mature, and a voracious predator. Suggest you go through your fish, and sort out accordingly.>
<Cheers, Neale.>
Re: Mastacembelus erythrotaenia; diet; health -- 08/04/09

Hi, thanks for your advice previously. Thankfully, after more than 2 weeks of not eating, Mr eel started to eat again. But only prawns.
<I see.>
What is the best way to get him to try new food? we have tried trick him with muscle in-between bits of prawn. He eats it initially then spits it out! He wont touch any dried foods, not that i thought he would.
There isn't really anywhere for me to dig up worms close by.
<Any bait shops? They usually sell earthworms ("night crawlers") and you can even buy worm farms from about £30 upwards that turn the stuff you put into the green recycling bin into earthworms. These are clean, don't smell, and are small enough to fit easily on a patio, in a shed, or somewhere else cool and dry.>
And he ate river shrimps once when we first got him, but every other time he ignores them. Even when they land on his nose!
<How odd!>
I am eager to try as you said prawns are not a great diet for him.
<Have you tried hand feeding? Spiny Eels are famously willing to feed this way, once settled. Long forceps help, and initially at least, use foods he takes, such as prawns. Once he gets used to feeding this way, you might try other foods, such as strips of squid, lancefish (which you get from fish shops) and of course earthworms. Cheers, Neale.>
Re: Mastacembelus erythrotaenia 10/2/09

Kind reminder. Still no reply received . And now my eel has started scratching like he has ick or something but still no visible signs of any illness! I tried to catch him but they're too damn fast and i cannot get to him!
<Replied to your question days ago. Check your inbox. If you can't find it there, it's up on this page, here:
Cheers, Neale.> 
This is BobF, I place all daily... And have seen the responses to your queries... Please check that you don't have this email inadvertently blocked (e.g. in your "junk" folder).
Re: Mastacembelus erythrotaenia
Thank you so much. Did not find it in my inbox but saw it on your webpage.
Cheers guys
<Happy to have helped. Cheers, Neale.>
Re: Mastacembelus erythrotaenia -- 10/3/09

Hi there guys!!! Current update!! My eel has started to lean on one side to scratch on the driftwood, substrate e.t.c but still no visible marks on his skin only some areas are "light grey" which i assume is from scratching himself on the wood maybe??? Please help.
I'm really puzzled here!
<As I have said repeatedly, likely stress between specimens, the weaker one now steadily losing good health as it eats less and spends more time hiding. The point is that this species CANNOT be kept in groups. Remove the second eel to its own aquarium, and it should get better. The grey mucous may be a sign of environmental irritation, but if you suspect bacterial infection, treat with a suitable antibiotic. Cheers, Neale.>
Re: Mastacembelus erythrotaenia, hlth...    10/7/09

Hey Neale buddy,
It's been two and a half days since i put the smaller eel onto a hospital tank(100 ltr) with only a pvc tube in and an Anubias, no gravel no nothing else. Still not eating he's too scared I've never seen him like this and i
fear for the worse.
<Likely unhappy in such a small aquarium. Mastacembelus erythrotaenia is a big, delicate species.>
Still no visible illness signs or whatsoever and i honestly don't know what to treat it with (Waterlife PROTOZIN maybe due to the fact that he was scratching its sides on the wood????)
<Do not treat with this product. It contains formalin (formaldehyde solution) and copper, both of which are toxic to Spiny Eels.>
Don't know what else to do...
<It needs to be re-homed. Cheers, Neale.>
Re: Mastacembelus erythrotaenia... please refer    10/8/09

I'm planning to finish my monster tank within a month but i don't know if he can last that long...And one last thing. The nitrates have gone up to 2.0 and i used water from my other tank which nitrates are 0.0! No foods left in or anything else. What is causing the nitrates to rise so quickly?
<Fish will produce ammonia whether you feed them or not, and ammonia ends up as nitrate once its been through the biological filter. Cheers, Neale.>
Re: Mastacembelus erythrotaenia... reading....!   10/8/09

So will daily water changes help?
<Apropos to what? Yes, multiple small water changes rather than one big one is usually a good idea. But provided you have 0 ammonia, 0 nitrite, and relatively low nitrate (20 mg/l or less) then your Fire Eel should be happy. I'd expect a 25% water change per week adequate under most circumstances.>
For the health of the fish too? (This way maybe he'll survive for another month)
<Certainly won't do any harm.>
He ate one small earthworm today but didn't want more... Good sign i suppose...
Thank you for all your support Neale and really sorry for bothering you this often.
<It isn't any bother.>
It's just because i love that little guy and i don't want to lose him :o(
<I sympathise; Spiny Eels are lovely pets, and Mastacembelus erythrotaenia in particular one of the nicest and best-looking fish in the hobby. But they aren't sociable, and aggression between individuals (perhaps the
sexually mature males?) is common. Cheers, Neale.>

Sick Peacock Eel??  6/11/09
I have a 125g tank that we recently switched from aggressive ( we had two Oscars for 6-7 years that died) to a semi-aggressive tank. It contains six silver dollars, three gold and three blue gouramis, a Plec, a spotted cat, four tiny Cory cats, and two peacock eels.
<I see. Now, you do understand that Spiny Eels aren't easy to keep, and small species like your Macrognathus siamensis find it very difficult to compete with other fish for food? While the gouramis and characins should be fine, the catfish might be unacceptable rivals at dinner time.>
I have had one of the eels for about three months and the other for about one month. They seemed to be thriving for a while, hiding during the day either in two small caves, the large shipwreck, or under the gravel, and coming out at dusk and traveling the tank all night.
<Another problem here: gravel. Without exception, the smaller Macrognathus species are best kept in tanks with smooth silica sand. Gravel damages their skin, and the result is a bacterial infection that starts off with streaks of white mucous and dead skin, then bloody patches, and eventually death. I have written about this here at WWM, here:
Much as I like Spiny Eels, I don't rate them very highly as species for the casual hobbyist, and the vast majority of spiny eels die quite soon after purchase.>
Recently after a water change (which we do weekly) one of the eels (the newest) came out and was writhing around and twitching almost as if it were having a seizure. This was about a week ago and since the eel has been rather lethargic hanging in the plants or hiding only its head. Today and yesterday it managed to find one of the caves and is staying inside with his head poked out. I noticed that its snout appears to be injured or maybe just pale.
<A suitable antibiotic such as Maracyn might help turn things around, but you certainly need to replace the gravel with sand as well, if you end up euthanising the one fish and hoping to keep the other.
I haven't seen him eating, but I rarely do as we feed the eels after turning out the lights.
<Earthworms are their favourite foods, though wet frozen bloodworms and Tubifex work well too. They will never, ever eat dried foods, whether freeze-dried, flake or pellets. Needless to say, those specimens that aren't scratched to death by gravel often end up starving to death because they're offered the wrong food or forced to compete with catfish and loaches. As I say, these are NOT easy fish to keep.>
Our water conditions are ideal, as we check them weekly also. Any suggestions for treatment or a difference in care? Should I move him to a hospital tank, and if so treat with what?
<Cheers, Neale.>
Re: Sick Peacock Eel??  6/11/09
Thank you for your fast reply!!
<Most welcome.>
Here's an update on the situation: We knew when buying the eels that they are not easy to keep. We're really not what you would call casual hobbyists, we have five different tanks and have been raising and even
breeding multiple types of aquatic life for several years. It just so happens that we've never been exposed to the spiny eels before and don't know much about them.
We did research before buying the eels, the only bad advice it seems we obtained was that gravel is an acceptable substrate.
<Indeed; you cannot expect to keep these Spiny Eels for long in tanks with gravel, period, end of discussion. They need a substrate made from smooth silica sand (be careful when selecting other types of sand to make sure they're "burrower friendly"). Floating plants are another key addition.>
We do feed the eels bloodworms and place them in the caves with the eels where the catfish cannot fit to take them.
I haven't seen any white mucous on the eel, only the damage to its snout, it appears that he has either rubbed off or scratched off the tip of his snout. After getting a better look at it, I can see a small white dot
directly in the center of the snout that looks like bone!
<This is precisely how things start to go wrong. These fish burrow by pushing their heads into the sediment. In the wild, that would be mud, sand, and organic detritus such as leaf litter. So the head is plenty strong enough to work its way through without damage. But gravel is far too hard, scratches away the skin, and eventually creates wounds that become infected. Once the infection begins, these fish are difficult to treat, and anything other than the most minor infections seem to be fatal in most cases. It's actually quite obvious why you can't keep them in tanks with gravel when you think about it, which makes it even more of a shame that so few retailers and hobbyists seem to be aware of the issue.>
Is there anything I can do to heal the wound? Is Maracyn still the recommendation?
<Yes, together with a different substrate. Cheers, Neale.>

Fire eel, fdg., hlth.  6/6/09
Hello my name is Crystal
i have owned my pride and joy(fire eel) for almost 2 years not and she is doing great with in the last 2 - 3 weeks she has been getting really picky with food (which i know is normal)
<Indeed; but few Spiny Eels resist tasty, juicy earthworms! So if you have an "organic" garden (one where sprays aren't used) go collect some earthworms from under stones, flower pots and rotting wood! Leave your Spiny Eel to starve for a couple days, and then introduce one or two live earthworms at dinner time.>
and she's not nearly as active as she normally is she is in a 90 gal tank but today i noticed that she has a red sore or bump on her cheek/ mouth
<Could well be a bacterial infection following physical damage, e.g., from trying to dig into gravel or from fighting with another fish. Treat with an antibiotic such as Maracyn promptly to prevent further problems.>
i have salt all ready in the tank and the normal chemicals with the right levels for everything
<A bit concerned you mention salt, since this species doesn't really need salt. But in any case, review water chemistry and water quality: you want moderately hard water, an approximately neutral pH, 0 ammonia, and 0 nitrite. There's no real need to add salt, since these fish don't come from brackish water habitats.>
just wondering if this maybe an injury or could it be a parasite as i have never have seen anything like this
<Yes, they can get parasites, but the usual way this happens is when people make the BIG mistake of feeding them feeder fish. Spiny eels certainly don't need live fish in their diet, and goldfish and minnows would be doubly bad because these are rich in fat and thiaminase. Used over the long term, goldfish and minnows can cause major, probably irreversible, problems. So, assuming you haven't used feeder fish, then parasites are probably not an issue. If you've used feeder fish, then almost anything could be wrong, and only a vet can tell you precisely what the matter is.
In case I'm not making my point clear, aquarists should not use feeder fish they've purchased from pet stores or bait shops, and if they must use them for obligate piscivores (which your eels aren't) then those feeder fish need to be home-bred and gut-loaded members of a "non toxic" species, such as Mollies or Killifish.>
thank you and just looking for a response on if i should worry thank you hope to here from you soon
Crystal & Jess
<Do see more about Spiny Eels, here:
Cheers, Neale.>

HELP!! My peacock eel is dying!! 03/29/09
Hello All!
My spiny eel is dying; breathing rapidly, jerking, flopping all over the tank.
<Oh. Doesn't sound good.>
Water condition is ideal, I can detect no visible signs of disease/trauma on the eel, everything appears ideal, everything is great except all of a sudden he is acting strange, even laying on the sand upside down and on his side.
<If water quality and water chemistry are good, I'd actually be suspicious of toxins: paint fumes, varnish fumes, anything children might "accidentally" have dumped in the aquarium. Spiny Eels are fairly sensitive fish, so toxins, copper, formalin and various other things can cause them to reach badly. In this case, I'd do a big (75%) water change to flush out any potential toxins, taking care the new water matches the old in terms of pH and hardness.>
Is there anything I can do to make him better or help him out in any way?
What could have caused this? Please help!
<Do have a peruse of this article:
Cheers, Neale.>
Re: HELP!! My peacock eel is dying!!  03/29/09

Thank you, Neale, for such a fast response.
<My pleasure.>
I have been up all night watching my eel. I actually did a 70-80% water change at about 2am and I do think that helped.
I don't know if you remember my other letter, the one where my eel disappeared? It appears as if I have found him/her. I was vacuuming my larger Gourami tank (the one that the eels were in originally and the one disappeared from) and after removing the large artificial rock I looked to the bottom of the tank and, lo and behold, there he was, big as life!
I quickly removed him and put him in my eel tank and he has been fine since. He must have been hiding inside the rock because I completely emptied the tank, sand and all when I moved the eels.
<Does happen. Back in the prehistory of the hobby (i.e., pre-1990) it was very common for people to discover colonies of fish living inside (underneath) their undergravel filters, often things like Kuhli loaches.>
It is very curious though, because I drained all of the water out of that rock no less than 4 times to vacuum the tank, so if he was in that rock he was without water for 15-20 minutes at a time.
<Many fish will tolerate long periods out of water, provided they are damp.  At least some Mastacembelidae have an air-breathing ability that allows them to tolerate swampy conditions, so these would be good candidates for a list of fish able to live out of water for many minutes.>
There is no way he could have been in the gravel because I used a rather large substrate that would have been impossible for him to burrow in. It is the other eel that appears to be ill.
After the water change this morning he did eat some and did some sort of fast moving dance with the other eel on and off for most of the night. Is it possible for them to be mating?
<These are Macrognathus siamensis, right? That's a fairly sociable species, so may be merely some sort of dominance assertion ritual. Spiny Eels breed extremely infrequently, and when it happens, it seems more luck than anything else. Females are much deeper bodied than the males though, so sexing two similar sized specimens of the same species should be fairly easy. Males are broadly circular in section, maybe a little compressed from side to side, but females are dramatically more compressed, especially when sexually mature.>
One of them is most definitely more full-bodied than the other, since I bought them at the same time, from the same shop.
<OK; well, given this, may well be a male and a female. Little is known of their precise breeding habits. In Baensch, reference is made (under the incorrect name, Macrognathus aculeatus) to one breeding success. The male was 11 cm, the female 19 cm, so those are possible sizes they need to be to breed. Mating was described (translated) as "vehement" (heaven's only know what the original German word was, though presumably this means it was boisterous) and a 1000 eggs about 1.2 mm across were produced. These hatched after 3 days, and after another 3 days the fry became mobile and
started feeding on Radiolaria and Cyclops nauplii. Conditions: 24-26 C, pH 7.2, 39 (!!!) degrees dH. Other reports from memory include one where the eggs were laid among floating plants. So far as I know, the adults do not extend any kind of broodcare, and should probably be removed after spawning. Or put another way, if you came across some eggs, I'd remove them to, e.g., a floating trap so you could watch them. If they did spawn, I'd like to hear about it! It's really extremely rare.>
So I do think he is better, but now it is day time and while the other eel has gone under the sand this one still is out. My plan is to perform daily water changes until he is back to normal. Any other suggestions?
<Not really; observation is the order of the day, and perhaps tempt them with some earthworms if you have some (yet to meet a Spiny Eel who wouldn't take these yummy morsels!).>
Should I add some Pimafix just in case?
<Possibly, but if you use either this or Melafix, understand these are at best preventatives (like dabbing a cut with antiseptic ointment) and not really much of a remedy otherwise.>
<Good luck, Neale.>

Re: HELP!! My peacock eel is dying!! 3/30/09
Alright, my eel is still alive, but will not bury herself and just lays on her side. She does have some red marks on her. I have attached pics.
<Yes, I see them. Does look like a bacterial infection; Erythromycin or similar will be the only option that I can think of. Spiny Eels are prone to these infections. The addition of a small amount of salt may benefit; Baensch recommends 1-2 teaspoons per 2.5 gallons.>
Also, while we're at it, can you identify her for me?
<Macrognathus siamensis. See for example, here:
In the hobby, this fish is often called Macrognathus aculeatus or the Peacock Eel.>
I have two identical, one more deeper-bodied, but identical all the same.  They are supposed to be Peacock Eels but you know how that goes...
<This is what they are, likely a boy and a girl.>
Anyway...I have removed her to a hospital tank with sand, heater and airstone. I even put in a plastic floating plant so she would feel more secure. I have not added Pimafix to the water yet as I wanted to ask you what you thought of a salt bath.
<At dose mentioned, though as a *supplement* to the antibiotic, not an alternative. This is bacterial, and it does require a systemic approach to fix.>
I was not sure if a salt bath would harm her or not so I wanted to ask first.
<Spiny eels tolerate salt well, so unlikely to do harm.>
She seems listless whilst in the tank but when I was trying to net her she really gave me a run for my money, so that makes me feel a little better.  I really do not want to lose her. I have spent hours upon hours watching her eat, and watching her watch me. What do you think the red marks are?
<Specifically, they're signs of inflammation, or where the blood vessels have been blocked by bacteria.>
She did not have those until last night. I went to work about midnight and they were just starting and I got home about an hour ago and she looks like this. That's when I put her in the hospital tank. Everyone else in the tank is fine, as far as I know.
<Quick, treat her!>
Thank you a million times for your help. I am rather new to the hobby and have read many of your articles and letters before buying my eels.
<Try Maracyn first; if that doesn't work, switch to Maracyn 2 as that catches different types of bacteria.>
Thank you, thank you, thank you!
<Good luck, Neale.>

Re: HELP!! My peacock eel is dying!! 3/30/09
Thank you again and again!
<You're welcome.>
Just so I am clear...dose with Maracyn,
<Several doses, across several days; follow instructions to the letter! Remember to remove carbon, if used.>
and add salt?
<I would, at the dose suggested by Baensch.>
Or should I leave off with the Pimafix for now?
<Pimafix won't fix anything Maracyn can't.>
And also, are we talking table salt or aquarium salt?
<Aquarium ("tonic") salt, though non-iodised cooking salt will work too.  Don't use marine salt mix: that would alter the pH and hardness.>
Sorry for all the dumb questions, but I really want to get this right.
<The only dumb question is the one not asked...>
Also, a friend recommended using Lifeguard; it's made by Jungle, and it almost seems as if I have used it before in my son's tank. Will this be safe for my eel?
<No personal experience. Would recommend not to mix medications.>
How do I know if it is safe or not?
<Depends on the ingredients; would tend to avoid copper, formalin when treating Spiny Eels.>
Also, the picture of the eel you sent does not look like my eel at all.  She has spots on her tail but she has dark stripes running along her sides.
<The only sharp photos you sent me are of the back end, and that matches Macrognathus siamensis. But do also check Macrognathus aral, another commonly traded "peacock eel".>
Again, thanks a million for all of your help.
<Cheers, Neale.>
Re: HELP!! My peacock eel is dying!! 3/30/09

I have attached a couple photos I took a little while ago.
<Appears to be Macrognathus aral, or something similar. Do see here to peruse some other members of the family:
http://www.fishbase.org/identification/specieslist.cfm?famcode=432&areacode= >
I ended up putting her back in my eel tank because I noticed my heater wasn't working properly and she was acting decidedly worse. I added the Maracyn to the tank; it comes in little packets of powder and the directions say to just dump it in but as you can see in the photos it leaves little white clumps everywhere.
<How odd.>
Will it be ok to dissolve it in water next time?
<That's what I'd do. Add the powder to a cup of water, stir well, and then pour across the top of the aquarium in a zig-zag motion from left to right, so that the solution gets evenly distributed.>
Again and again, thanks!!
<Happy to help. Cheers, Neale.> 

Re: HELP!! My peacock eel is dying!!  4/1/09
Hello again!
<Hello Lana,>
I have enclosed a photo of my poor eel taken this morning. I am broken-hearted.
She is still breathing, but that is about all. With as advanced as her infection is, do you think she has a chance of pulling through?
I just don't know what to do. I started her on the Maracyn -2, or whatever it is called, the other one you suggested, yesterday.
Part of me wants to believe that the fact that she is still alive shows she is getting better, but the logical part feels like she is just slowly dying and needs to be put out of her misery (that sounds so awful).
<I doubt she'll recover. The problem with Spiny Eels is once they get sick, it really is difficult to heal them. I don't really know why this is, but to prevent this happening in the first place is my usual approach, e.g., in terms of soft sand rather than gravel.>
I have looked deep into myself and I absolutely CANNOT end this eel's life.
<Never easy. Is she showing any signs of getting better? E.g., more movement, healed skin. If not, would recommend overdosing with Clove Oil.
This first sedates the fish, and then eventually the fish suffocates as its breathing rate slows down.
It's a peaceful way to go, according to vets. A litre of water with 20-30 drops of clove oil should do the trick. Stir well, and then add the fish.>
I trust your opinion, so I am asking you what you think: Should I end her suffering (or find someone who can) or let this go on and see what happens?
<Sorry this isn't ending well. Good luck either way, Neale.>

Re: HELP!! My peacock eel is dying!! -- 04/07/09
Hello Neale,
<Hello Lana,>
I am sorry to say that my poor eel is gone. I used the clove oil yesterday morning. I feel absolutely horrible. I know that it was the right thing to do because she was suffering horribly, but I still feel sad.
<I sympathise, and am sorry to hear this.>
Thank you so much for all of your help with this. It is such a good feeling, knowing that there is someone I can count on for help during times like these.
<Thank you for saying this.>
When I was first thinking about buying eels I Googled "peacock eel" and came across the Wet Web Media site; I sat for hours reading the articles you wrote on spiny eels. When I say I couldn't have done it without you, I really mean I couldn't have done it without you. Thank you so much for that.
<I do hope the other eels are healthy and happier. Once settled down and feeding they can be long lived, even hardy fish. But they don't travel well. Good luck, Neale.> 

Peacock Eel Floating?  3/18/09
Dear Crew,
In my 30 gal tank I have had a ~9 inch peacock eel for years who is generally happy and shy and hides in the plentiful plastic plants and small rock caves. When threatened, it burrows into the round pebbles but
normally is comfortable enough to just hide in the plants. The other fish (various tetras, Leaffish, algae eater, swimmers, etc) leave the eels alone.
<Not a big fan of pebbles in Spiny Eel tanks: sooner or later the fish gets scratched, and then secondary infections set in. Small species like Macrognathus siamensis should be kept in tanks with smooth silica sand. Do see here:
Recently it became so bloated that it floats when still, so has to anchor under some plants or position itself under rock ceiling. I change water and vacuum every 2-3 weeks and chemistry is OK except nitrites/nitrates can occasionally get on the high end of acceptable. I add aquarium salt according to directions.
<How much salt? And why? Macrognathus siamensis isn't a brackish water fish, and while there may be value to salt as a therapy under some situations, continual exposure to salt can cause problems for freshwater fish. One reaction is bloating, and indication that their osmoregulatory system has been overloaded in some way. Unless you're keeping one of the truly brackish water species, like Macrognathus aral, there's no need to use salt.>
Other fish in tank get flakes. Ran out of frozen bloodworms for eels and switched to frozen brine shrimp for the last month or so. I hand feed this eel and my other younger peacock eel. Every now and then I put in some pieces of cooked egg or salmon for variety.
<Don't use egg. Not a natural part of their diet, and can cause constipation.>
I have noticed some bubbles coming from the big one's anus on two different occasions so wondering if this is just a bad case of gas that will work itself out or if something else is going on.
<So far as I know, spiny eels aren't air breathers, so I wouldn't expect them to expel gases out of their vent in the same way as certain air-breathing fish.>
Ready to lay eggs?
<Possibly; female Spiny Eels are distinctly laterally compressed because they are substantially deeper bodied than the males. Sometimes, certain fish become egg-bound in captivity if not kept with males: even if the eggs don't develop into fry, the simple act of spawning "clears out" the female reproductive tract.>
I adore my eels and would appreciate any help you can give.
<Very difficult to say precisely what the problem is. As mentioned above, there are at least three possible factors. Gravel simply doesn't work with spiny eels in the long term, and nondescript bacterial infections are the almost invariable result. The regular addition of salt to freshwater aquaria causes more problems than it fixes, and isn't recommended because it can cause precisely the sort of bloating problems you're experiencing here (see, for example, Malawi Bloat). Finally, egg binding is an occasionally reported problem among species of fish that refuse point-blank to spawn in captivity. While there isn't much you can do about egg binding beyond adding a male and hoping for the best, I'd also recommend treating with a suitable antibiotic (e.g., erythromycin or Minocycline) while adding Epsom salt at a dose of 1 teaspoon per 5 to 10 US gallons. These will have the combined effect of (hopefully) killing the bacterial infection while
restoring the osmotic balance within the fish. Stop with the regular salt though!>
Thanks very much!!
<Cheers, Neale.>

Peacock Eel looking pale   2/3/09 Hi, I have a peacock eel who is becoming very pale, almost pinkish, and his spots seem to be transparent. He's about 6-8'', and I've had him for a year now in a 55 gallon tropical tank. I've had past problems with bacterial infections due to sick feeder fish, and over the course of several months lost the majority of my fish. The eel never seemed affected though. I treated it and decided to change my tank to African cichlids since I only had 7 fish left. The tropical tank was kept at 80 degrees with a pH of 7.8. I had colorful decorations with dark blue and purple pebbles. The eel was always the typical color, light brown with a lighter belly and dark eye spots. When I changed to a cichlid tank 2 days ago, I changed the dark larger gravel to a sand colored crushed coral which upped the pH to 8.2, temp is still 80 degrees. I also added some brown flagstone for the cichlids (I only have 4 yellow labs under 2"so far). The eel has been very active since the majority of fish were lost, and he eats well. His behavior hasn't changed since the tank was switched over, there are no sores and his skin is smooth and intact, but his color has definitely paled. My question is this: Can a peacock eel change colors to better match it's surroundings? or, Could it be the pH? I really love my eel, and want to do whatever I can to keep him healthy. I would hate to know I'm causing him to fail in this tank. Any advice would be appreciated. Thanks, Beth <Hello Beth. The answer to your specific questions are [a] yes, fish do change their colours somewhat, depending on their mood and environment; and [b] pH is possibly an issue here. But let's expand this slightly. Spiny Eels are notoriously prone to bacterial infections, and shouldn't be brought within a mile of feeder fish. End of story. Whether or not they actually eat the feeder fish is immaterial, simply putting feeder fish in the tank is an unacceptable risk. Secondly, Spiny Eels are very easily damaged by anything other than smooth sand. Gravel and pebbles are totally unacceptable for the smaller species. Most people who try eventually end up with a dead Spiny Eel. This happens so often I just consider it mandatory to keep the small Macrognathus species Spiny Eels in tanks with a smooth silica (silver) sand substrate. Always take care not to use things like Tahitian Moon Sand as these are "sharp" sands. The manufacturers actually state that these sands are incompatible with burrowing fish, but too many aquarists ignore this, and wonder why their Spiny Eel gets shredded and eventually infected with a bacterial infection of some type. Crushed coral is inadvisable for a variety of reasons; partly because it raises the pH and hardness, and partly because Spiny Eels can't burrow through it. Coral sand could be mixed with silver sand at a ratio of up to one part coral sand to four parts silver sand, but any more than that would also raise the pH and hardness excessively. There are Spiny Eels from Lakes Tanganyika and Malawi, but the Peacock Eel (Macrognathus siamensis) is not one of them, and consequently has no place long term in a Rift Valley Cichlid aquarium. Even if the water chemistry won't kill it immediately, the aggressive behaviour of the cichlids will, either directly, or through making it difficult for the Spiny Eel to feed. The native Spiny Eels are "used" to cichlids and actually prey on them, or more specifically, their fry. They don't burrow but instead hide in the rocks, and while not commonly traded they are available from time to time. If your Spiny Eel has changed colour, my gut feeling is that this may be partly to "blend in" but could equally easily be a stress reaction. This fish doesn't belong in this tank, and shouldn't be kept with Malawi cichlids, period. Do see here: http://www.wetwebmedia.com/FWSubWebIndex/spinyeelsmonk.htm Hope this helps, Neale.>
Re: Peacock Eel looking pale (Time to get creative!)   2/3/09
Thank You, <Most welcome.> Here's my next question... I don't know anyone with a tropical tank I would trust not to kill my eel. I'm also afraid to give it to a fish store just to suffer elsewhere. Do you have any suggestions for where I could look if I need to give him up? <The best advice is to get in contact with a local fish club. Many have an online forum, so even if you can't travel, you can still communicate. That's probably your best way to learn the better stores or fishkeepers in your area. I'm in England, so my knowledge of the aquarium hobby in Florida is somewhat limited!> I spoke with at least 4 different fish store guys (not Petsmart) all told me the eel would do fine in the cichlid tank. <It's possible they were thinking of the African species of Spiny Eel, such as Mastacembelus ellipsifer, which do indeed cohabit with (some) cichlids quite well. But the reality is that people sometimes know rather less than they think they know. It's always important to research topics independently, though stuff that's been edited by experts, whether books, magazines, or web sites like this one. In this case the problem is that, for example, Malawi cichlids and Spiny Eels need completely different food. Mbuna are mostly herbivorous, but will eat meaty foods if offered, and this makes them sick if given to excess. Spiny Eels are carnivores, but slow ones, so most insect larvae or whatever put in the tank will be eaten by Mbuna long before the Spiny Eels find them. Again, the pH and hardness suitable for Malawi cichlids is much to high for Asian Spiny Eels. Yet again, the cichlids want coral sand and lots of rocks, whereas the Spiny Eels need soft sand and feathery plants. It's difficult for me to see how you can satisfy the needs of the Spiny Eels and the Mbuna in the same system, even hoping that the Spiny Eels will be smart enough to avoid being bitten or harassed by aggressive cichlids.> My choosing cichlids was dependent on the ability for the eel to thrive, and they all claimed the crushed coral was not so coarse as to damage him. <Coral sand probably won't scratch him, but it's far from ideal.> Today he's hanging out over the aerator bubbles and he's jumped into the filter once (he only did that when I treated the tank with Pimafix and it irritated him) so I know he's not happy. <Indeed.> I really can't set up another tank, but I want to see him where he'll be happy, and he likes a lot of space. Thanks for your time <Here's my workaround. You have so far only Yellow Labs, right? Go back to a regular planted community tank. Yellow Labs have been bred so much in captivity known they should adapt to such conditions. Keep the pH around 7.5, keep the hardness around, say, 12-15 degrees dH, and make sure the water is well oxygenated. Use plants that do well in such conditions (most will be fine). Use soft silica sand on the bottom, and arrange some rocks in heaps for the cichlids to use, while leaving plants in other areas. Don't get any more Malawi cichlids (at least not without talking to me first!) and just stick with species that should adapt to such conditions. All else being equal, I'd expect such a community to just about work. Yellow Labs are hardy and not aggressive, so compared with Malawi cichlids generally, they're fairly good in communities. You will need to feed the Spiny Eels at night to make sure they get enough to eat, but other than that, I can't see any major problems. Not textbook cichlid keeping, but viable. Cheers, Neale.>
Re: Peacock Eel looking pale   2/3/09
I apologize for all the questions, but... I forgot to add that I also added 2 tablespoons of salt to my 55 gallon tank on Saturday (advised by the fish store guy after checking the water) and I wondered if the salt would irritate him more than the pH which was increased from 7.8 to 8.2. Our house has a water softener, which was never a problem before. If I do some slight water changes will this help him until I can figure out what to do? Will the salt burn his skin, or is the alkaline just way too high? Thanks, and again sorry for all the here and there questions <Who told you to add salt to a tank with Malawi cichlids? There's a fair consensus that salt is one cause of Malawi Bloat, and should not be used as an additive in this way. As a component alongside Epsom salt and baking soda, marine salt mix can be used to create a home-brew Malawi salt, but it should not be used alone. You also shouldn't use water from a domestic water softener. Very bad for fish. Spiny Eels are actually fairly tolerate of salt, and some species occur in brackish water. But just to be clear: use plain, un-softened tap water, with no salt, in your aquarium (but with dechlorinator, of course). Cheers, Neale.>
Re: Peacock Eel looking pale   2/3/09
THANK YOU SO MUCH! For future reference, what other types of cichlid can I add. I want to stay with the less aggressive. Are "electric blue" or "peacock" ok? They were suggested by the fish store. Thanks, Beth <No, I wouldn't go with Aulonocara spp. in the tank I described earlier. Even the Labidochromis is pushing it, but they're fairly small, peaceful and adaptable. To be honest, I wouldn't add any other cichlids until I had seen the tank running stably for a while, three months at least. Concentrate on midwater things if need be, barbs and the like. Cheers, Neale.> 

Red fire eel with a spot   1/10/09 Hello My name is Karen B. and I have a 40 gallon tank that has been running for the past 22 years with fresh water tropical fish. The tank has two power heads, 4 inches of gravel, 40 pounds of decorative rock, many live plants, an under gravel filter plates. I do my water changes every other week and vacuumed part of the bed every month. Many years ago I worked in a fish only shop where I fell in love with fish keeping. I used to breed fresh water fish and got my red fire eel as a one inch baby from a customer. He's now almost 20 years old, about 22 inches long, a good eater (hand feed Calf. black worms) and has had many tank mates over the years. Most have died of old age and some he did eat in the beginning. About a month ago he developed a spot on his side, it's round and looks a little fuzzy it's about the size of a small pea. He's had this spot for a while and it never got any bigger or seemed to bother him. I did treat the tank with a fungal medicine for a week with no help because I didn't know what else to do for him. Now I've done my water changes and in the past few weeks he has developed several white freckles on his belly running the full length. I've been web searching and found very little information on how long fire eels live or anything about his spot(s). I talked to the local pet shop who told me to try here. So here I am question in hand. None of his tank mates are ill or have any spots. I know eels don't do well in medicated tanks for long periods of time because they are skin fish I really don't want to loose him. Worried Karen <Hello Karen. Fire Eels (Mastacembelus erythrotaenia) are -- in common with all Spiny Eels -- prone to skin infections. Left untreated, these can quickly cause the death of your fish. The usual problem is that people decide to keep their Spiny Eel in a tank with gravel and/or jagged rocks. Spiny Eels are burrowers, and their small scales are easily removed if they try to burrow into gravel. Once the scales are gone, their first line of defense against opportunistic infections is breached, and the chances of things like Fungus and Finrot dramatically increase. I really can't stress this point strongly enough: small Spiny Eels (like peacock eels) should never be kept in tanks with gravel, and the larger species, such as Fire Eels, should only be kept with smooth gravel and smooth rocks. Also check how clean the gravel or sand in your tank is: over time, both become "dirty" and should really be cleaned with each water change. While the bacteria on the gravel or sand are usually harmless, in large quantities they can cause problems, the classic example being bacterial erosion of catfish barbels. I mention this because damage to a Spiny Eel's belly is very common the first sign of bacterial problems. Now, given your specimen is a whopping 20 years old there's no way you're a "newbie" at this, and your basic mode of fishkeeping must be essentially sound. But I would recommend looking through your tank for anything dirty, sharp or jagged, and removing it. On the other hand, I suspect your fish is to some degree getting old, and his immune system may be getting weaker, and even in the best aquarium, he may become more prone to infections, no matter what. Next up, how to treat! Spiny Eels are sensitive to copper or formalin. An antibiotic would be a good first pass treatment, something like Maracyn or, if that doesn't work, Maracyn 2 (these treat different sets of Finrot bacteria). Apply any medications carefully, and as always, take care to increase aeration of the water during the treatment and keep a close eye out for signs of distress. Alternatively, look for a copper-free medication suitable for use in marine tanks and/or with copper-sensitive species such as Stingrays and Mormyrids. The addition of a small amount of tonic (not marine) salt to the water may be useful too; when keeping this species, Baensch recommends 1-2 teaspoons (about 6-12 grammes) per 2.5 gallons (about 10 litres) and I don't have any quibbles with that. Spiny Eels generally tolerate salt extremely well and tonic salt won't affect pH or hardness (as opposed to marine salt mix, which would). Higher salinities might be used to treat Fungal infections directly, though by itself salt doesn't have much impact on bacterial infections like Finrot. I'd expect a Fire Eel to handle salinities up to SG 1.003 without any fuss at all, and quite possibly a little higher. Tea-tree oil treatments such as Melafix might have some beneficial support function, but I wouldn't rely on them to treat the infection at hand here. Spiny Eels are fantastic fish, and the Fire Eel in particular. Wishing you luck, Neale.>

Re: red fire eel with a spot   1/11/09 thanks for your quick response I am worried about my old man in the tank. I did a water change today and will do another partial tomorrow. I've printed out the email and will head out the pet shop today. Thanks again. Karen <Happy to help. Cheers, Neale.>

Egg bound Aethiomastacembelus elipsifer eel Female African Eel Full Of Eggs   8/23/08 Hello. I have an Aethiomastacembelus elipsifer eel that is frequently very full of eggs. I've had her for about two years now. I tried to get a male for her, but unfortunately the young eel I bought turned out to be another female. My problem is that my eel is egg bound. She did not want to eat a few days ago, so I put in about 2 tablespoons Epsom salts per 10 gallons into her tank, and raised the tank temperature a little over a degree so that it is now 80.8 degrees F. She became active the next day, and begged to eat, but she still looks pretty big. I have not fed her for three days because I want to give her body time to reabsorb the eggs. She normally eats frozen mysis shrimp with liquid vitamins or freeze dried Tubifex worms. I did look at some of the old WetWebMedia files, and found where it was mentioned using a bath of 1 tablespoon Epsom salt per gallon of water, but she's in a heavily rocked large tank and I'd rather not have to dismantle all the rocks to get her out. I will probably give her a light feeding today. I hope that she will be okay. My thought was, if she doesn't continue to improve or goes downhill, would it be okay to roll her mysis shrimp with some Epsom salt so that she would ingest a grain or two? She eats from my hand, so I'm sure it wouldn't be too difficult to do if it would be safe. Thank you. Kelly IMG_8236.JPG < With freight being so expensive and the dollar losing its value in the world market, shipments of wild Lake Tanganyikan are becoming increasingly rare and very expensive. Not many retailers are willing to spend the time and money to bring in wild fish. Trying to find a rare African eel can be very difficult these days. In 2002 I was diving in Lake Tanganyika and we found many baby eels in the shallower areas of the lake near weed beds. The water temp there was 84 F. This makes me think that maybe the eels are coming up to the shallower areas to spawn and the elevated water temps may aid in spawning. Since you have already elevated the water temp and have observed some recovery, I would suggest trying a couple more degrees instead of adding the salt to the diet and see if things get any better.-Chuck>

Sick fire eel  7/4/08 Hello, <Hi there> I am desperately seeking help for my sick fire eel. I have had several fire eels in the past and have done very well with them but I have a very Sick one on my hands right now. My eel is about 25 inches long and very was very healthy looking, about 3 inches tall and nice and full, I have never had one That was this big before. <Is very good size> Then one day I noticed (and I check on my fish every day, so it looked like the eel was fine one day and was having problems the next) my eel was upside down in his tube. My eel kept trying to get upright but would just keep rotating around, (I don't know his sex but I'm just going to refer to my eel as he) he looked fine on the outside, he has No visible marks or sores but he is starting to breath very heavy. I have a feeling it might have something to do with his diet, since he is so big I have been feeding him minnows and almost everyday. <Mmm...> From what I have read from your web it wasn't the best thing for him and he may have overeaten? <This or parasites... a lack of some nutrient...> I went to the fish store and have read the questions on your web site, but I haven't had any luck making him any better. Myself and the fish store I deal with thought it must be some kind of parasite or infection inside (from the minnows) <Yes, most likely> so I bought some prozi-pro <Something like this... Praziquantel is only for worms... what if this is a protozoan?> and tried that. No luck. I did water changes and went back to the fish store and they suggested trying TC Tetracycoline <Mmm, not this antibiotic either> (spelling might be off I'm at work and don't have the box with me) I have tried a full cycle of that with water changes and still no luck. It has been over a week and he is getting worse, I feel so bad for him, he is breathing really labored and heavy at times, I feel so helpless. He now just Hangs upside down at the top, it's almost like he is paralyzed, he try's to move sometimes but just can't. The only other fish I have in the tank are My discus, so I want to be careful I don't stress them out either. Please Help, Thank You, Cherie <Read on WWM re the one-time use of Metronidazole/Flagyl. Bob Fenner>

Re: sick fire eel 07/07/08 Thank You for the advise it sounds like it might have helped but unfortunately he died this weekend, it just killed me to see him suffer. Now I know for the next time that your site exists and I can go there for Help. It was a very sad loss Thanks again, Cherie <Ah yes. Thank you for this follow-up Cherie. BobF>

Peacock eel seems sick    2/16/08 Hello I have a 30 gallon freshwater tank. I set up my tank about 3 weeks ago, and I bought a peacock eel about 5 or 6 days ago, and he seems sick now. We bought him at Wal-mart (yes I have learned my lesson about that) and they couldn't really tell us anything about him. <Never, ever buy a fish that neither you nor the store clerk knows anything about. I cannot begin to tell you the number of disasters that begin this way.> Luckily, I read online that he ate dried bloodworms, which I had on hand from a while ago. <No chance, and certainly not when newly imported from the wild, which will likely be the case here. Newly introduced Spiny Eels overwhelmingly need live foods, ideally earthworms, Tubifex, or bloodworms. Once settled in they will eat (wet) frozen bloodworms and the like. But not dried foods. Also, they will not compete with other benthic fish, so cannot be kept in tanks with, for example, loaches or catfish.> Unluckily, he doesn't seem to want to eat them. <No surprise at all.> He seemed fine for a few days, he was swimming around quite a bit, mostly seeming to chase his own reflection against the glass. <He's trying to get out from this puddle he's trapped in (an aquarium) that completely lacks any edible foods.> Yesterday we noticed he wasn't swimming around as much, and I started becoming more concerned about the fact that I had not seen him eat. <I'd be worried, too. Go into the garden and dig up a couple of small earthworms. Put in the tank and let the eel eat them at his leisure, i.e., without competition.> So today we went to our local fish store and they sold us some feeder fish (the very small kind, since he is only about a three inch eel). <No no no. These fish should not be given feeder fish. Spiny Eels are among THE most sensitive fish on the planet when it comes to infections, and sticking cheap fish bred in squalid conditions (i.e., a feeder fish) is sort of like asking Typhoid Mary to cook your lunch.> The woman assured us that he would eat them. <She told you she knew nothing about the fish, and then assured you this was the correct diet? You should have smelled a rat.> But when we got home we noticed the eel was just laying over the plunger that is holding the heater onto the tank. We added the feeder fish and he was completely uninterested in them, even when they went so far as to swim around his head. <Not his normal diet. He eats worms, insect larvae, and small benthic invertebrates of various types. Mostly taken from on and in the sand. One of the common mistakes people make is to keep these fish in tanks with gravel. This you MUST NOT do. These small Macrognathus spp. Spiny Eels forage by burrowing through the sand, using their prehensile "nose" to winkle out prey. In a sandy tank they will dig in during the day, and slither about at night. In a tank with gravel they often starve. On top of that, gravel damages the mucous layer on their bodies, making them INCREDIBLY sensitive to bacterial infections. By far the majority of Spiny Eel deaths come from: starvation, bacterial infections, and fish jumping out. Anyone wanting to keep these fish MUST plan around these, and set up the tank accordingly. Do please see here: http://wetwebmedia.com/FWSubWebIndex/spinyeelsmonk.htm > The woman at the fish store had also informed us that the temperature might not be ideal for him, so I first turned the heater up, and now the temperature is at about 76 degrees F. I am trying to bring it down to about 73, to accommodate the other fish in the tank, but the temp does not seem to be going down. That is my first question, how do you bring the temp down? <Takes time.> After the temperature was right I did some more research, and discovered that ammonia could also be a big problem, so we tested it and discovered it was a bit high, so we added some ammonia reducing tablets. <There's no such thing as a "bit" high, any more than being a "bit" pregnant. If you detect ammonia, it means you have a major problem: too much pollution in a tank that doesn't have enough of a filter to deal with it. The amount of ammonia is largely irrelevant. Review whether the stocking of the tank is appropriate to the size of the tank, whether the filter is mature and/or sufficient capacity. Check whether you are overfeeding.> The ph was also a little high so I added some ph reducer. <NO NO NO NO NO -- inexperienced aquarists shouldn't EVER mess about with pH reducers (or raisers). Please understand: the pH value itself doesn't really matter; what matters is how fast pH changes. If you're testing the pH but have no idea what the general and carbonate hardness levels are in your aquarium, then you shouldn't be messing about with the pH because you likely (certainly) don't have enough knowledge to do so safely. So forget about this. Instead check whether the pH is the same a week after a water change as it is immediately after you do the water change -- that will tell you if the pH is stable or not. Do please read here: http://wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm > I also did a partial water change of about 20% and added some stress coat. I thought maybe one of these factors might have been what was causing the eel to be distressed, but he is still hanging on the side of the heater. <I bet.> He does seem to be swaying a bit more now, but I am really starting to get worried. It even got to the point where we thought he was dead because we saw the other fish sucking on him. Luckily when we tried to scoop him out of the tank he swam away, which was a huge relief. <To be honest, I think this fish is doomed UNLESS you [a] make sure the aquarium is appropriate (i.e., has sandy substrate, no bottom feeding fish, good water quality) and [b] you start offering healthy live foods that this fish can eat. Yes, it will eat (wet) frozen bloodworms later on, but right now we're talking triage, and that means live earthworms small enough for the fish to eat easily. For a 3-4 inch Spiny Eel, we're talking 1-inch worms. There's no discussion here. If you don't do these things, he'll be dead in a week. Period. End of story.> I even tried to load the dried bloodworms into a turkey baster and squirt them right in front of his face. He still did not respond, except for to move a little. He certainly did not show interest in the food. I read that they would eat earthworms. I am thinking about going and buying some worms from my local bait shop tomorrow and seeing if he will eat these. <YES!!!> What should we do? <Read the articles linked above, and ALWAYS read before buying your fish. Spiny Eels are in my top 10 fish beginners should NEVER keep. They are very difficult fish for so many reasons. Are they nice fish? Yes. Are they intelligent? Very. Can they be tamed and fed from your hand? Certainly. Are they a fish for the average community tank. Not a chance.> I am new at this hobby and do not know how to tell what is wrong. My first instinct is that it is he is not eating, but I am also worried he is sick with something. I have some multi-purpose medicine but I have also read that you shouldn't use most medications on them since they do not have scales. Any advice you could give would be greatly appreciated. Thanks, Erin <Good luck, Neale.>

Re: Peacock eel seems sick  2-16-08 Thank you so much for your advice. He is doing much better today. I woke up and he was swimming around the tank, and some of the feeder fish are gone. <Very good. But I can't stress too strongly that feeder fish are poor food for most fish, and should be avoided where possible. The risks of introducing diseases, as well as malnutrition, are simply far too great. Once settled, Spiny Eels will even eat chunks of prawn; so really the issue up front is to get them eating a few earthworms just to fatten up a little.> I am now regretting that we got them at all though since now I am worried about him getting sick. <Don't be *too* disheartened. These are rewarding fish, and once settled in, not difficult to keep. The problems are setting up the tank "just so" and then getting a wild-caught fish feeding. Most people fail in these regards, and end up with a dead Spiny Eel.> I am definitely going to go today and get the sand substrate and earthworms. <Cool.> To clear one thing, the woman at the fish store was supposed to know what she was talking about. It was the people at Wal-mart that didn't, but when we went and got the feeder fish we went to a different local fish store ran by people that were supposed to know what they were doing. Needless to say, I will not be going back there for advice. <Too bad. A good aquarium shop is an amazingly useful asset. Regardless, with a bit of reading and a good aquarium book to hand, you'll be fine. Trust me: this is how many of us start!> I must say, I feel rather silly about this whole thing. I thought keeping fish would be much easier than this, but I have definitely learned my lesson. <Keeping animals is never "easy", whether cat, dog or fish. But in the big scheme of things, fish are pretty straightforward, especially once you understand the basics and take care to choose fish appropriate to your local water chemistry and skill level.> I will be much more careful and do much more research in the future, as I would hate to think that a poor animal died because I was too ignorant to take care of it. <Indeed!> Thanks! Erin <Enjoy your fish, and good luck! Neale.>

Fire eel with pop eye and cloudy eye -- 10/30/2007 Hello All- <Emily.> I am so glad I have found WWM! I happened to stumble upon your page while doing research for my sick Eel. I'll try and keep this short. For the last 3 weeks my fire eel has had cloudy bulgy eyes. (almost looks like he's wearing goggles) Is this pop eye? <Yes sounds like a bacterial infection of the eye.> His appetite is a little decreased but he is still nibbling at his blood worms each day (not as much so in the last 2 days). He has also gone pale in color over the last week. I really don't want to loose him, I'm a novice fish owner! He's in a 75 gallon tank and I've had him for about 6 months. He has lots of hiding places and none of the other fish bother him. Last week I started treating him with Ampicillin <...is for gram negative bacteria.> every other day for 5 days since Erythromycin <...is for gram positive bacteria.> and tetracycline <...treats gram negative as well negative bacteria of some types.> has not helped. I have also done two 50% water changes within the last week. His color has improved a little but his eyes are still very cloudy. He just lays on his side hiding in his cave all day. He has always been a pretty mellow eel. I had my water tested at a local fish store and everything seemed fine. <Numbers would help, especially hardness and nitrates.> What should I be doing for my eel? <Although fire eels most commonly occur in soft water habitats like some streams, swamps and even flooded rice fields and only rarely are found near estuaries, they may do much better in hard to slightly brackish water in captivity. The exact reasons therefore are unknown and may be related to some interaction of ions (hardness, salinity, carbonate hardness) and the accumulation of possibly toxic compounds in the tank water (e.g. nitrates), that, due to dilution, does not occur in nature to such extent. Although adding salt to the standard fish tank can well be considered an antique technique from times when the need for partial water changes was unknown, I'd suggest to increase the salinity of the water to reach a specific gravity of 1.002 (roughly 3-4 grams marine salt from the pet store per litre). That should improve the constitution of the fish and won't kill your filter bacteria. In addition I'd try to improve the diet by offering a variety of foods, because if he only ate bloodworms, he may also suffer from a lack of vitamins. Try earth worms, little shrimps and also soak the blood worms in vitamins from time to time prior to feeding. You have already used a lot of antibiotics, so I'd get a test kit and check if nitrites are 0 all the time. Nitrates should be below 20 ppm for good healing conditions. If another antibiotic has to be used (I hope not), try Maracyn.> Thank you and warm regards! -- Emily <Also have a look at http://www.wetwebmedia.com/FWSubWebIndex/matacembelids.htm and the linked files above. Hope that helps and your eel gets well again. Marco.>

Tire track eel medicine need help  6/30/07 Hi my name is Donna, <Ahh, "the lady", and one of my sisters praenomens> My husband and I have a 40 inch tire track eel <Nice!> that was with an Oscar who came down with an internal parasite <... of what sort, nature?> I know what to treat her with but what is safe for the eel and spiny eel (spiny not showing symptoms yet). He has all the same symptoms the Oscar did. Curled up, not eating and on the bottom of tank. Also had 2 hi-fin banded sharks that were in there also need to treat everybody. Do you know of any medicine we can buy that is safe. <Mmm, best to treat sequentially with an antiprotozoal (my choice is a one-time administration of Flagyl/Metronidazole) and an anthelminthic (Prazi/quantel or Levamisole...). All protocols, cautionary statements for this are posted/archived on WWM... These are relatively safe, efficacious compounds. Bob Fenner>

New peacock spiny eel, sys., fdg.    6/2/07 Hi! thanks for all your advice > I got the eel, he's about six inches long and looks well fed. no white blotches on his skin or signs or irritation. <Very good.> > he is hiding under the gravel in my tank right now, but there is a cave in there that I hope he will move into when he feels more comfortable. <Please replace the gravel with sand as soon as possible. In my experience, small spiny eels die when kept in tanks with gravel. The problem is that they try to dig into the gravel, scratch their skins, and get infected with various bacteria. Once sick, they are impossible to treat. I have seen this happen so often that keeping small spiny eels in tanks with gravel strikes me as a virtual death sentence. Now, changing to sand is neither difficult not expensive. Silica sand (also known as silver sand) can be obtained at any garden centre for very little money. Choose the "smooth" not "sharp" grade for obvious reasons! A 25 kg (~50 lb) bag of the stuff costs about £3 ($6) at my local garden centre, so in other words there is no excuse for not buying and using the stuff. Plants love it, as do most fish. The main problem it causes is getting into the filter if big fish (like plecs) splash it about. It can potentially become anaerobic if you allow organic material to decay under a great depth of the stuff. To avoid this, simply keep it clean, use Malayan livebearing snails to aerate the sand, or just keep the depth to a minimum, say, 5 cm (2 inches). If you go for the shallow sand bed approach, you obviously can't keep plants with roots, but epiphytes such as Java fern and Anubias are fine.> > my question is, I've tried both frozen bloodworms and live mealworms so far, both of which he has left uneaten. he appeared to smell the mealworms a little, but didn't eat any. I have been able to find live butterworms, waxworms, and superworms, whatever those are, are any of these suitable food? or would I be better off trying earthworms? <Spiny eels are 100% nocturnal when imported, so be sure and put the LIVE bloodworms and/or Tubifex in at NIGHT. Remove anything likely to compete, such as catfish and loaches. Catfish and loaches are simply NOT at option with small spiny eels. Earthworms are also very popular with spiny eels, and perhaps the ideal reconditioning food for helping settle newly imported specimens in. Once you know the fish is eating, then you can wean them onto frozen alternatives. To be honest, spiny eels have to be close to the top of the list of fish that should be quarantined first so you can get them feeding before being placed in a community tank. They just aren't, by any measurement, "good community fish" -- they need a great deal of special care, and the vast majority of specimens die within a few months. Although basically hardy and very adaptable in terms of water chemistry, their demands for sand and live foods make them among the most difficult "common" fish in the trade. Larger species, ironically, are easier to care for, being indifferent to whether you use sand or gravel and being relatively easy to feed with things like earthworms, live river shrimp, or even (home-bred) feeder guppies. The small species, including all those sold as "peacock spiny eels" are simply difficult fish best kept by experienced fishkeepers in single-species or at least specially designed aquaria.> > there were also a lot of small snails in the tank I got him from, and I was wondering if he was maybe eating those, since he appears well fed. he looks like he's of a good girth, and explored all around his tank last night. if he has been eating snails, are they a good long term food source that I could maybe raise in a separate tank? <No, your eel isn't eating the snails. He lacks the jaw structure for that. Snail-eating fish tend to have strong jaws and flat teeth for crushing the shells: things you see on puffers, loaches, and certain cichlids and catfish. Spiny eels are nocturnal opportunist predators. They have deeply-cleft jaws that allow them to swallow surprisingly large prey. The smaller species feed primarily on worms and insect larvae, while the bigger species are more or less piscivorous (though in captivity are easily fed on prawns and other chunky invertebrate foods). > thanks! > Tori <Hope this helps, Neale>

Spiny eel with grey patches -- 05/04/07 Hello Wet Webbers! My name is Linda <Hi Linda. Marco here with you today.> and have a question for you.  I have done some research and have not found the info I am seeking, so I hope you don't mind my long question. <Please see http://www.wetwebmedia.com/FWSubWebIndex/spinyeeldisfaqs.htm for similar questions.> I enlarged the print cause I just had Lasik done and am having some trouble reading my computer screen. <Hope you get well soon.> I added an 8" fire eel to my 150 gallon FW community cichlid tank.  His tank mates are 3 keyhole cichlids, 2 port cichlids, 2 gold and 1 green Severum, three fire mouths, one 5" chocolate cichlid <quite some competition for the eel with regard to food.> a handful of Corys, a few rummy nose tetras, half a dozen tiger barbs and three clown loaches.  He was fine for the first six months, but about 6-8 weeks ago he started "peeling".  He has gray "bald" spots on part of his body now. He swims well and is a hearty eater. <Good to hear.> A couple weeks ago I did have a very bad outbreak of ick (saw a chocolate cichlid that I just had to have and didn't set up a quarantine tank, I should know better) I had to treat the whole tank with copper safe. <I'd use copper products in bare bottom hospital tanks only. Now you have to get rid of it with water changes and by filtering with activated carbon, and hope none remains in the substrate.> Everyone survived and all is well except for Earl.  He continues to look worse.  Since the "bald" spots are the only symptom, I thought I would give him some time to heal on his own.  I also thought maybe he was molting, or something <No, certainly not.>. His gray blotches do not look like fuzzy fungus or bacterial spots. Just large patches. <Spiny eels are prone to skin diseases such as the one you describe. It probably is a bacterial infection possibly associated with a fungus.> I have spent a great deal of time watching the tank lately and have never witnessed any of his tank mates attacking or picking on him. I do 75% water changes every two weeks. <The latter two actions are good practice.> The pH is 7.5-8, 0 nitrites and well below 20ppm of nitrate.  He eats frozen bloodworms and brine shrimp. I am going to set up the quarantine tank and move him tonight to see if maybe someone is harassing him at night. Can you give me any suggestions as to what may be going on with Earl? Should I medicate him or just observe him since he is eating well? <If filtering your display with activated carbon does not improve the situation, quarantine him and add 1g/l marine salt. This is a mild treatment often successful in similar cases. Also be sure to provide pristine water quality in the quarantine tank. If that does not show any improvement in about 10 days to 2 weeks you should consider the use of antibiotics in your hospital tank. Also, read the FAQ linked to above. > If someone is picking on him, I would guess it is the Firemouths. Oh yes! I have a mixture of small to med. gravel size <hope the grains are well rounded, because spiny eels like to bury.>, soft driftwood, smooth rocks, a large strawberry pot, and plastic plants in the decor. The temp. is right around 77 degrees. Thank you so much, you guys provide a great and valuable service to the tropical fish world. Linda from WI. <You are welcome. Hope your eel gets well again.>
Spiny eel with grey patches II -- 05/05/07
A few more facts on my eel. When I feed my fish their frozen food,  I throw a chunk of bloodworms in a 2 quart pitcher and fill it with tank water. When the worms are defrosted,  I swirl it around to break apart the chunk and dip the pitcher into the tank. I hold it below the surface enough for Earl to slip in and eat his fill before I dump it out for the rest of the fish.  Using the large pitcher works well because when you dump all the water out it swirls around and disperses well so everyone has a chance of eating. This way I know Earl is getting enough food. <Nice feeding technique. Could be improved by avoiding the polluted thawing water getting into the tank.> Also I have never seen him burrow into the gravel. <He'd do that if he was harassed by the cichlids.> He hangs out under the driftwood and will also hang on the water intake tube support. For the salt treatment, I am guessing 1g/l  marine salt is one gram per liter?  <Yes. Cheers, Marco.>

Fire Eel Disorientation  4/26/07 I contacted you guys quite a few years ago about my 130 gallon tank being infected with Cyanobacteria.  Ever since then I've never been able to get rid of it but once a week I siphon off the slime algae carpets off the bottom and it looks good for another two days or so. <Cyanobacteria ("blue-green algae") grow in tanks without aquarium plants usually because the water has high levels of nitrate and phosphate. There's really not much you can do about it in the average "tank buster" aquarium without actively reducing the nutrient levels in the water. Oh, and by "without plants" I mean any tank not set up specifically for rapid growth of higher plants. A couple of Java ferns won't make any difference either way!> I've tried more powerful lights, no lights (made the Cyanobacteria grow slower but made everything else worse), phosphate filters, etc and none of it has ever stopped or even slowed down the speed of the growth. <Phosphate (and nitrate) filters generally can't help the eutrophic conditions in heavily stocked tank buster aquaria. They are designed for use in marine tanks and planted freshwater tanks where the water quality is already very good. These chemical filters "polish" the water a little more, by scrubbing out the phosphate (or nitrate). But they are utterly overwhelmed when placed in a tank buster tank unless used in vast numbers and replaced/recharged on a weekly basis.> I've had the tank set up for over 5 years now and the inhabitants are a clown knife fish, fire eel, spiny eel, and three rope fish. <Nice collection of fish.> I've heard before that clown knife fish shouldn't have any tankmates smaller than them but I guess these guys have learned to live with each other or something, 'cause they never pick fights. <Often, fishes are inoffensive towards fish they grow up with -- they view them as part of the scenery, I suppose.> When I'm cleaning the eels' caves the even sometimes hide behind the clown knife in the corner and he has no problem with it. Anyways, I discovered recently that erythromycin apparently kills off Cyanobacteria while being quite safe for plant life, the fish, and it also doesn't harm the biological filter all that much.  So, I picked up some Maracyn 1 and followed a dosing schedule that I found while researching on the internet.  It said it was a rather ful powerful dosage to kill the Cyanobacteria rather than create a resistant strain of it, yet it was far less than the Maracyn instructions listed to cure bacterial infections and such.  It said to add 2.5 mg/L of it one day 1, 2, and 4.  Then 1 mg/L on day 8.  Between these days I should do frequent water changes and siphoning dead Cyanobacteria and debris out of the tank.  Due to having only two packages of Maracyn 1, I ended up actually adding only about 2.0 mg/L for the first few days. <Honestly, in my opinion a totally pointless exercise. The Cyanobacteria grows in your tank because of the nutrients in the water. Even if you killed off any single bacterium in the tank (which won't happen) more would get in from the air and in a month or two you'd be back where you started. Unless you reduce the phosphates and nitrates to as close to zero and keep them there permanently, the Cyanobacteria are going to come back. Period.> So, here's my problem now.  I added the first dosage two days ago and then the second dosage yesterday.  I could already see that the slime algae was beginning to thin out, but when it came to feeding time I saw that something was wrong with my 5 year old fire eel.  He wouldn't eat and he was swimming around restlessly and seemed disoriented.  He was also swimming completely upside down the entire time.  When he hid underneath his cave he would lie upside down as well. <First: check water quality. Second: perform 50% water change. Third: perform another 50% water change. Quite obviously you've done something the fish doesn't like, and it's good odds that the massive die-off of bacteria that's causing pollution in the water, using up oxygen, and perhaps releasing toxins in the water as well.> I added some aquarium salt at one teaspoon per gallon and boosted the temperature from 80F to 83F. <Why are you doing this? Fire eels aren't brackish water fish and don't need salt. Raising the temperature and adding the salt both reduce the amount of oxygen in the water, further aggravating one likely problem. Please, unless you have a clear reason for doing so, NEVER change the water chemistry or aquarium conditions simply as a knee-jerk reaction. Fish don't like changes. Oh, and bin the tonic salt. It's useless stuff. Honest.> This morning the fire eel was lying on top of a tall piece of driftwood upside down, and he rarely lies out in the open. <Sounds extremely serious. Have you done those 50% water changes yet?> There's no visible wounds or discoloration on him and he doesn't look bloated or breathing quickly.  I tested the water and the ammonia was 0 ppm, nitrite was 0 ppm and nitrate was 32 ppm. <Well, the nitrates are part of the blue-green algae problem...> I hope you have some suggestions as to what I should do 'cause I really don't want to lose my eel. <Do the water changes. Increase oxygenation in the water. Present a votive offering to the Fish Gods.> It's strange that it happened as soon as I added the Maracyn 1, but everywhere I read it shouldn't be causing any problems to the eel.  Thanks for your help. <My basic philosophy is that without medical or veterinarian advice, aquarists shouldn't use antibiotics, period. There's a reason people go to medical (or vet) school to learn about those drugs. Unfortunately, in the US at least, some antibiotics are freely available. Please resist the urge to use them needlessly. As you're discovering, they are powerful medications that can have unpredictable results to those not trained in their use. In the meantime, just do more water changes to bring the nitrates and phosphates down, and remove the Cyanobacteria the old-fashioned way: with elbow grease.> Dayton <Cheers, Neale>

Re: Fire Eel Disorientation  4/26/07 Thanks for the information.  After I sent the last message yesterday I went home and did the 50% water change, but I guess that I should have done another one afterwards. <You can never do too many water changes, assuming water chemistry remains constant.> I was also planning on doing another water change today and every day until he gets better. <Good idea.> Unfortunately, I really don't think he'll even survive the rest of the day.  I woke up this morning and he's floating at the surface of the water, just barely breathing. <Definitely not promising. If this was me, I'd change all the water NOW. Nothing to lose at this stage, and my assumption is the antibacterial treatment and/or dead Cyanobacteria is the cause of the problem. Siphon out everything organic in the tank, thoroughly sluice the gravel in the process to remove everything organic that is decaying. Replace with 100% new water at identical pH/hardness/temperature. Use dechlorinator but otherwise don't add anything. Maximize aeration. Keep temperature at a steady 25C/77F. Switch the lights low/off to reduce stress. My hope would be by returning to optimal water conditions ASAP, your fire eel might recover.> About the Cyanobacteria though... is the chance that great that I'll get more of it in my tank simply from the air? <Yes. Bacteria travel as air-borne spores, among other ways. When some blue-green algae dries up somewhere, some of that becomes encysted, floats away on the breeze, and settles out wherever. That's why you find the stuff in gutters, bird baths, etc.> I had the tank set up for about a year with no problems, but then I added some aquarium plants that weren't fully cleaned and quarantined I guess. <You have to be ruthless here: strip away *any* leaves with blue-green or hair algae on sight. Usually, the algae colonize sick plants (or leaves, anyway) so you're not losing anything by trimming the plant.> That's what brought in the Cyanobacteria.  I have 4 other tanks (smallest one 30 gallons) and none of them have ever had problems with Cyanobacteria before. <Blue-green is very difficult to predict in terms of where it will occur. "We" as a hobby know the conditions it likes, but as you say, sometimes it's a problem, sometimes not.> But, I added a decoration to one of my tanks just last month (the decoration was in the 130 gallon 2 years ago and has been dried out since) and within a week I noticed Cyanobacteria growing in that one. I figured that as long as I keep the supplies I use with the infected tank away from the clean tanks, I won't have any problem.  It's been working so far for 5 years now. <Maybe, maybe not. I'd not put any money on this. But blue-green algae is more a visual problem than a life-threatening one, so I'd always recommend manual removal of blue-green during water changes rather than chemical (algicide) treatments. Massive die-offs of algae (or plants for that matter) can consume oxygen rapidly and dump unwanted pollutants into the tank. The advantages of getting rid of the algae quickly do not, in my opinion, offset the risks of the other. Cheers, Neale>

Re: Fire Eel Disorientation  - 05/02/07 So, since last Thursday I did a 50% water change on Thursday and Friday night, then switched to 30% water change every day since then. <Sounds a good start. Water changes help with most fish problems considerably.> On Friday morning instead of having trouble swimming the fire eel was floating at the top of the water.  Once in awhile he'd try to swim down again but he couldn't even get down a few inches. <Sounds very odd, but swimming problems can be caused by all kinds of diseases/injuries/environmental factors. I've seen dwarf cichlids swim upside down because I put too-cold water into the tank.> I was hoping the water changes would be helping but they don'seem to be.  I figured he'd be gone within a day or two but now that it's Tuesday I'm starting to think that there's something else wrong with him.  He's still breathing normally and has no discoloration but he still can't get below the surface.  He looks slightly bloated maybe so I was wondering if eels have a swim bladder like fish do? <A very good question. Most benthic fish have reduced/absent swim bladders so that they stay close to the bottom of the river or sea without being caught up by the currents. I do not know if spiny eels have swim bladders, and haven't been able to check in my usual references. My *guess* would be they have them, but of a reduced size and importance.> I think that he's fine other than the fact that he can't swim downwards.  I even gently lowered him to the bottom of the tank and when I let go you flew quickly to the surface as if he was full of air.  My girlfriend wants me to euthanize him and if I can't do anything else that's what I'll end up doing, but it just seems to me that if I could figure out what's making him float he'll be fine. <Provided he's feeding and remains in good condition otherwise, I'd tend to leave things to settle down for a while. Swim bladder problems will often fix themselves over time. Provided good water quality, keep the temperature constant, avoid stressing the fish, and try and get it to eat if you can.> If it was a bacterial infection it should've been cleared up when I added the Maracyn so maybe he ingested a rock or something? <Swim bladder disorders are what medics call "multi-factorial", meaning no-one really knows what causes them in every case. Possibilities include lack of fibre, mechanical damage, genetics, etc. Since a spiny eel doesn't eat plant material, lack of fibre probably isn't the issue here. But I'd certainly raise the temperature a little (by 3-5 degrees C) and continue using something mildly antibacterial such as Melafix or even tonic salt. Whilst I don't usually recommend the use of salt in freshwater tanks, spiny eels are one group where small amounts (around 1 gramme/litre) have been used therapeutically with success.> Thanks. Dayton <Good luck! Neale>
Re: Fire eel with disorientation -- 05/02/07
I had previously added salt when he was first showing the strange symptoms and was then told that I shouldn't have. <Fire eels are not among those spiny eel species that have been caught in estuaries, but they won't be killed by 1-2 g salt /l. However, it is mostly used to treat skin diseases and should not be in their tanks permanently.> I guess that I'll just leave him floating there and try to keep feeding him but tomorrow will have been a week since he first started having trouble swimming.  The main problem that I'm worried about is that when he's floating about 1 1/2 inches of his belly is slightly above the surface of the water and gets dried out. <You are right. That can be a problem.> Every morning and every hour or two when I'm at home I hold him gently under the water for a bit to moisten the skin again, but I'm worried that the drying of the skin is hurting him.  His belly seems to be getting a blotchy look to it where it's submerged and is tacky and slightly dry whenever I push him back under.  What can I do to keep his entire body underwater and wait till he gets better? <For puffers that swallowed air and had similar difficulties, I used a large net to keep them down until the air was spit out again. You may want to try that, too. There is some gas in your spiny eel, but it is unclear in which part of his body and how long it takes until it leaves. I'd speculate, aside an possible internal bacterial infection, the use of Maracyn in the display let to the death of some bacteria (maybe your Cyanobacteria), which as part of their decomposition released some toxic substance. But that's just a theory. Keep on doing water changes to keep the nitrates and any other possible toxins down as Neale suggested. Hope the best. Marco.> Dayton

Fire eel with white scuff -- 04/12/07 Hi, <Hi John.> I have a fire eel and I am reasonably sure he has a internal bacterial infection. He has white scuff like marks on his body and labored breathing and hasn't eaten in some time (2 weeks). <You probably mean external bacterial infection, since you can see white scuff on the outside. Internal refers to the interior of the fish and is hard to diagnose. In addition it would be good to know, if there are any other fishes in this tank.> I've been treating him for some time with Maracyn but no luck. I know it's imperative to get him to ingest his medicine but since he won't eat, do you have any ideas? <First of all I'd use antibiotics only in a hospital tank. They tend to disintegrate when exposed to light, tank substrate and tank water. Some even kill beneficial bacteria and can mess up the nitrogen cycle (Mardel, the producer of Maracyn, states their product shows no adverse effects). Test your water, especially nitrites, nitrates and pH. Large water changes won't hurt. Spiny eels are not prone to bacterial infections when high water quality is provided. If your pH is around 7 slowly increase it to 7.5-8.0. Fire eels show a higher resistance to bacterial and fungal infections in hard water and lower end brackish water, so you may slowly raise your specific gravity to 1.003. In addition you need a better diagnosis. Search WWM for freshwater diseases, especially Columnaris and read the related FAQs. If you still think your eel has a bacterial infection, use baths as an alternative to treatment in the display tank. Do daily one hour aerated and pH adjusted baths in two times the Maracyn concentration recommended for a permanent treatment in the display tank. Repeat for at least 5 days, even if the disease seems to be gone. If this treatment does not work and the eel is still alive, do the same with an antibiotic for gram negative bacteria such as Maracyn Two.> Also, is Maracyn the most appropriate choice of antibiotic? <It works well for gram positive bacterial infections, which are the most common type of bacterial pathogens in freshwater.> I know things look bleak but do have any suggestions? <Check water quality; do water changes, slowly adjust the pH to 7.5-8.0 and (if you can do that) the specific gravity to 1.003 (over one week), get a better diagnosis and treat accordingly. Good luck. Marco.>

Re: Sick Fire Eel (FOLLOW-UP)  - 1/22/07 Hello again, this is Katey in regards to the sick fire eel (update).  I've got the water quality (nitrates) much better using frequent small changes and distilled water.   <Ah, good> The gray slimy splotches on the eel are now gone, with her stripes becoming a little brighter. <Very good!> She is more "with it," still eats well, and is active and curious.  However, she seems different, not her usual self... she'll sometimes lounge kind of sideways or curved upside down, like she's just free floating. <Behavioral improvement will "take time"... perhaps months> When I look in at her she'll notice me and immediately turn up smartly and watch me alertly, so it's not like she's stuck that way, semi-unconscious.  Also, while the colorless splotches on her cheeks filled in black again, she now has an almost reticulated pattern on her body of colorless, bleached skin, with a pale underbelly. <Stress coloration... this too will pass>   I've managed to get a few good pictures of first her belly, then her net pattern going down her body.  From these pictures, is there anything you recognize?  She is, besides the skin and seeming loss of equilibrium, much better.  Your help and time is very appreciated!  Thanks, Katey <Thank you for this update... stay the course here. Bob Fenner>
Re: Sick Fire Eel (FOLLOW-UP)   1/24/07 It was very heartening to hear these last symptoms will pass, and she's over the hump.  Keep up the good work with WetWebMedia, and thanks for your assistance with my sweetest eel! <Thank you my friend. Life to you. BobF>

Injured peacock eel - please help  - 1/22/07 Hi Crew, <Kim> I've searched site and can't find the info that I need, and I'm pretty desperate, so I'm writing in hopes that you can give me some advice. <Will try> I have a peacock eel who is about 5 inches long. He lives, happily until today, in a 75 gallon planted tank with gravel substrate. Today my 11 year old daughter picked up the large castle decoration in the tank to look for a snail that she couldn't find. She sat it down and when she saw that it was crushing one of the plants, she pushed it over. My eel was apparently next to the bottom of the castle and got pinned under it. I walked in the room right as she was pushing it over and since she's not supposed to ever stick her hands in the tank, immediately rushed over to see what in the world she was doing. I saw the eel sticking out from under the castle, about two inches below his head.  Needless to say, I got the castle off of him in a flash. He swam (if you can call it that) away, but under his gills is red and he looks bent in the middle when he's still. I managed to scoop him up in a small plastic container and moved him to my hospital tank. The thing is, I don't have a clue what to do for him now, or even if there is anything that I can do for him. <Mmm, not much "to do"... their gills are red naturally... and if in initial good shape, mastacembelids/spiny eels do tend to heal rapidly... I would move this fish back into the main system myself> As I write this, he is laying on the bottom of the tank, curved in a loose C shape, but he's moved a couple of times since his transfer. Any suggestions are greatly appreciated. Thanks!  Kim <No medications suggested... Just time, patience and hope. Bob Fenner> -- Kim Jones

Sick Fire Eel    12/26/06 Hello, I'm Katey, and I was hoping you could help me with a problem with my fire eel.  A week or so ago she began getting pale spots on her face, as if the color was bleached out. <A bad sign> She also began acting listless, letting her head droop sideways instead of alertly poking it out of her hiding place. <Something amiss here environmentally...> However, she still ate ghost shrimp (her favorite food) just as voraciously as before.  I did massive research but didn't find anything that really fit... she didn't have "fungus" on her yet.  Water tested  o for nitrites but nitrates were high (close to 80 ppm?). <Yikes... way too high> However, I had just done a 45% water change a week or so before. <Too much percentage at one go... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwh2ochgs.htm and the linked FAQs file above>   A few days after presenting with the pale spots, she developed a grayish, slimy material on her body in various areas.  This sounded like columnaris (except nothing really around her mouth), so I began treatment with Maracyn plus after a 15% water change for the nitrates (Tuesday will be day 5).  My concern is that she is also occasionally having crazy frantic thrashing spins around the tank (lasts 5-10 seconds), and I'm not even sure it's columnaris! <Is not... primarily... something in the water... perhaps consequent with the massive water change...> She still acts lethargic but I thought her skin cleared up a little, though not sure.  Her appetite is good but she is definitely not herself.  Her tank-mates, a tire track, 2 clown loaches, and an African butterfly, show no sign of disease and are acting very healthy.  Any ideas/help would be very appreciated!!  Thank you very much for your time!  Katey <What re your water quality tests? I would use activated carbon, a pad of PolyFilter in your filter flow path here... Stat! Bob Fenner>
Re: Sick Fire Eel, need to add...    12/26/06
Hi, Katey again...I wanted to add onto my last email about my sick fire eel.  She is REALLY flipping around now...she seems to be absolutely desperate to itch. She goes on 100mph spins that looks like she is trying to itch her body with her nose.  Even worse, she beats herself against the wall, decorations doing this... I'm afraid she'll kill herself doing that! I hope this gives you more clues... Thanks! <... your water... Bob Fenner>
Re: Sick Fire Eel   12/27/06
Thanks so much for your advice...my water tests are the Jungle 5-in-1 strips... I've heard that they could be inaccurate, but that's all I have at the time... hope to be getting better tests though.  I will follow your advice, and update you with (hopefully) a good report!  Oh, and I did read that linked article...I will be switching to 15% every 2 weeks. Again, thanks very much!!  Katey <Thank you for this update Katey. Bob Fenner>

Starving Eel  9/2/06 Hi, <Hi Gillian, Pufferpunk here> I have a problem with my yellow spiny eel.  (At least that's the name it was sold to me as.)  It's very small, only about 2.5 inches.  I've had it for about 5 months.  I've had no problems up until now.  I have read that some people have problems with eels not eating and as a result, they lose them within a few weeks.   <True but it can take longer sometime, for an animal to slowly starve to death.> I figured that wasn't a problem since my eel has been around so long and although I haven't seen him eat (but I do think I've seen him darting at daphnia), he's looked well fed.  Just yesterday I noticed that he looked terrible.  He is very thin and seems to have no strength.  I moved him into a smaller tank by himself over night with food.   <Most spiney eels only eat live food.  Mostly blackworms.  That's what their long nose is for--to scrounge the substrate for worms.> I was a little worried that maybe some of his tank mates have been stealing all his food and that might have been the cause of the problem (he's in with 3 neons, a ghost shrimp and a panda Cory cat).  However, he didn't seem to eat any of the food offered to him.  I put him back in the tank with the others and he still swims around, but he still seems weak, unable to burrow and he'll stop swimming in funny positions, like on his side.  The problem is that I don't know what to do.  If he's not eating, I'm not sure how to make him eat.  If it's some kind of infection, I'm not sure what it is.  His fins, colour and skin all seem fine.  He just seems unbelievably thin and his gills look red (although I'm really not sure if his gills seem red because he's so thin or if it's some kind of infection).  The water chemistry's a little off, which I plan on fixing right away with water exchanges, and I've added a little bit of salt (one tbs/ 5 gallons). <Weekly water changes are necessary to keep the water clean & livable.> I'm not sure if I should try a salt treatment.  Or if I should try something like Melafix (even though I'm aware that he doesn't seem to have any of the symptoms Melafix says it treats).  I'm not sure how much longer the fish will last.  Please help. <Neither can hurt.  I'd try offering live worms.  ~PP> Thanks Gillian

Eels Healing from Injuries Hello Once again Dr Fenner! <Anthony Calfo in your service, my friend, whilst Bob travels the great continent of Australia. I'm hoping he brings me back a cool accent instead of a tee-shirt when he returns <smile>> I need your advice regarding these 3 fire eels that I want to buy. The aquarium houses them together with a grown Cichlid in a 2 ft tank. I think the Cichlid must have attacked them before 'cos I can see that 2 of them have slight injuries. <a shame...mitigated by the cramped tank I'm sure> The 3 eels are about a foot long and are very fat. The injuries are such that I can see the whites of the flesh. The body is jet black but then I can see breaks in the skin that reveal the whites. It actually looks like a small scratch made by a needle. The injuries look very minor but I do want them to heal if I decide to purchase them. Its very rare over here (Singapore) to get eels at this size. <perhaps because they are delectable <wink>> Do you have any recommendations for medication? What can I do to help the eels heal faster?  <yes... an antibiotic combination of Furazolidone and Nitrofurazone (Jungle brand "fungus eliminator" for example). Eels are one of the few fish prone to true fungal infections. It will guard against bacterial infections as well> If I just put them in my tank will the injuries eventually heal?  <perhaps...especially if your tank is larger (it really must be)> I went back to the aquarium about a week and a half later but the injuries were still apparent.  <unusual and not a great sign... perhaps you should take them sooner to a better tank> They look pretty relaxed in the tank though but I think they'll be better off without the Cichlid. <certainly agreed> On a separate note, what kind of medication are suitable for eels with fungus or other skin problems? <above listed...and antibiotics in general are safe> I read that they are very sensitive to metals in the water and also some 'itch' medicine.  <yes... avoid copper and organic dyes like malachite and Victoria green and methylene blue> Should I put in some capfuls of Blackwater into the tank? Will this help them relax? <dim lights will work the same or better> You helped me identify the Caecilian I have several weeks ago and I really am grateful! =) I look forward to your reply once again. Yours Faithfully, Leonard Emmanuel <with kind regards, Anthony>

Tiretrack Eels 10/14/03 They have not had an appetite for 3 weeks and I am getting worried so please can any one that is an expert on them please help me. <I really could use more info.  These are Tiretrack eels?  How long have you had them?  What kind of food have you offered  them?  How big is their tank?  What are their tankmates?  Have you tested the water?  How often do you change the water?  After you answer all of these questions I'll be much better equipped to help your fish.  Just to let you know, the only food I have ever seen my eels eat is live Tubifex/black/bloodworms.> and if there is a phone #  I could call to give more detail please tell me. <I'm sorry, we have no phone service.  Emails to this address is the best we can do.> thanks Jeff  <Your Welcome, Pufferpunk>

Boiled Eel.. >Hi, >>Hello. >Wow incredible site. >>Thank you. >My sister has a tire track eel and it's sick, it has boils (?) on its back. That's how she described it to me. >>Sounds like ulcers, an open sore is my take on it.  This isn't good, though. >What might it be and how can we fix it? >>We see ulcers of this type most commonly on goldfish.  It's called septicemia (see here: http://www.fishbase.org/Diseases/DiseasesSummary2.cfm?discode=809 ) >Do you have any good references for info on curing disease/sick tire track eels? >>Not specific to tire track eels, but you can also search for treatments for SCALELESS fishes. >I read on your site that if it has sores it's likely to die soon? >>Maybe not so soon, but these afflictions can be very difficult to deal with.  It should NOT be treated in the main display, however. >She's very found of this eel as she says it has a lot of personality! >>I'm sure it does, and if you can, search further on http://www.fishdisease.net/ as well as looking for freshwater fish forums and sites.  Because these infections can by caused by many bacteria, treatment is rather like "blasting" with antibiotics.  Marina >Thanks, Cindy

Sick eel please help I have a Aethiomastacembelus elipsifer Tanganyika eel and it does not look like he is eating and has gotten very skinny. I was wondering if there was anything I could do to fatten him up. He is not very active and does not look very good. I have him in a 55 gal. with mainly a Tanganyika/Malawi setup. I have tried feeding him bloodworms, freeze-dried plankton, and flake food at night after I have turned the lights out and the other fish have already been fed. I even tried holding it in front of him and he will not eat it. He used to bury himself all the time and now he just stays in one spot out all the time. I am very worried about him. What should I do?   < These eels are very cool. I saw many different species in lake Tanganyika as few years ago. They ranged from little small 4 inch eels that would swim around like little sea horses to very large ones like fire eels. In the wild we saw them feeding on small shell dwelling cichlids in around the rocks. We caught them at night in minnow traps using very oily fish as bait in the trap. I would catch the eel and place him in a separate tank that is well covered so he won't jump out. Place a layer of fine sand on the bottom and a rock or cave that he can hide in. Make sure the water temp is at least 80 degrees. I would first try some live washed earthworms or some well washed black worms. Then I would get some feeder guppies and throw them in the tank. See if the eel will take the guppies out of your hand. If this doesn't work then maybe small strips or raw fish cut to bite sized chunks. In a large community tank these eels are reluctant to feed because of all the commotion the cichlids create. You eel may end up needing live fish all the time. -Chuck> Thanks, Jessica B.

Feeding peacock eels I just purchased a small peacock eel and was wondering if I was feeding correctly. He/she is about 4-5 inches long and I'm feeding shrimp pellets. I read in the information on spiny eels that they won't bite and chew their food. I don't think my eel's mouth is large enough yet to eat the shrimp pellet whole but I dropped a pellet near him (he's burrowed and sticking his head and part of his body out) earlier and it's gone now. Will they eat the pellets once they've softened? Or do I need to resort to frozen food (I live in a college dorm that allows only fish tanks and I don't have access to a store that sells live food so my method of feeding is rather limited)? <Please read here: http://wetwebmedia.com/FWSubWebIndex/matacembelids.htm > In addition to that, I was wondering what would be the best remedies for the most common infections, like ick. I'm using a product currently with my other fish called CopperSafe by Mardel (Active ingredient: Chelated Copper Sulfate) in combination with a product called MelaFix (it says it's safe to use with scale-less fish). CopperSafe seems to work really well with my other fish, including a pictus cat, who came in with ick. But you mentioned that metallic medications don't work well on eels. What should I look for in an anti-ick medication when it comes to peacock eels? Should I just dose the tank with non-iodized salt? Sarah <Please read over WWM using the Google search tool there, with these questions, product names... I would not use Melafix for anything, nor copper compounds on mastacembelids or pimelodid cats... Read my friend, before purchasing livestock, using toxic chemicals on them. Bob Fenner>

Fire eel 11/3/05 Dear Robert, I wrote to in July with regard to my 10 year old fire eel (in 90 gallon tank) that I have always treated with the Maracyn and CopperSafe. You recommended I get a copper (ion) test kit to monitor the copper level because Stresscoat (which I use all the time) can remove it over time. I purchased a freshwater kit by Aquarium Pharmaceuticals which reads from 0.25 thru 4.0. My measurement today is .25. Is this a treatment level?  <Yes... tween 0.15 and 0.30 ppm of free cupric ion> My old kit by Aquarium Systems (which I cannot find replacement packets for) read 0.15 thru 0.2 on the chart and it stated that this is a therapeutic treatment if maintained for 10-14 days.  I also would like your opinion on this: my fire eel has these blister like, or more like welts, on his sides. He has had these for sometime - they are not new. It reminds me of a hive like a human would get on their skin. And, he has grown up with a Pleco that appears to have an uncanny affection towards him. It's like their glued together, though I suspect the Pleco is sucking the slime off of him. <May be> Again, this has been going on for years. Your comments, please.  Thank you. Linda I. <I would keep an eye on the Pleco... try to keep it weaned away from the eel... perhaps with algae wafers... offered toward the evening/lights out. Bob Fenner> 

Fire Eels, Cestodes, and Praziquantel - 11/01/2005 Hello Crew! I have a 2 1/2 foot Fire Eel that appears to have tapeworms. He appears very healthy and gregarious in all respects, but periodically he discharges some white, flat, many inches long, substance which appears to cause him some discomfort, resulting in thrashing about the tank to dislodge it. Does not appear to be normal waste or a normal way to evacuate based on the discomfort involved and the color.  <Could indeed be tapeworms.... or other worms.> I have not been able to isolate any of this substance as the rest of his tank mates devour it immediately, <Ugh.> which of course means they also have worms if that is what they are.  <Agreed.> He is fed live worms and I know they can be carriers of tapeworms which has caused my concern. <Good concern.> I know he shouldn't have any medications with copper, and I was also concerned because he is scaleless, or nearly so anyway. Some of his tankmates are also loaches and Botias, so I have to worry about them as well since he is too big to quarantine and they and the rest of his tankmates would probably have to be treated as well, anyway. However, all his tankmates also appear to be quite healthy. What medication or treatment would you recommend? <Praziquantel would be my first choice, followed by Levamisole or Piperazine.... There are a number of products available for aquarium use, one being "Prazi-Pro". Any of these medications (or others for cestodes) will need to be administered via food, I believe.> Thank you for your time. He is a sweet little fiend, and I don't want the worms to cause him problems in the future. I wasn't able to find anything by performing a search for this item in your website. <Glad to hopefully be of service.> Marcia <Wishing you well, -Sabrina>

Fire eel, copper use 7/22/05 Dear Robert: <Linda> I have had my fire eel about 10 years and he is about 18-19 inches and very well rounded. <How nice... great pets, very intelligent> He is very aggressive and spooks easily and has had several injuries to his body over the years.  Only on one occasion did I almost lose him - my local aquarium shop said it sounded like an infection in his gills - heavy breathing - not eating or swimming.  I treated the tank with Maracyns I and II  and CopperSafe and he recovered.  I have used these products ever since, and having read on your webpage that eels are sensitive to copper I wonder if I should stop. <Mmm, no... just "be careful"... not to over-expose> I recently moved ( and the fire eel) to a new home which is on well water and I regularly treat the water with StressCoat and CopperSafe.  May I have your opinion on this treatment plan.  Thank you. Linda Itoh <Mmm, I would get, use a copper (ion) test kit... and know that StressCoat will remove/precipitate copper. Bob Fenner>

Poorly eel... Ps. Sorry for such a long email,  but I thought I'd tell you as much as I could,,, also forgot to add, All the other fish seem ok... And the eel never seemed to eat anything... I got some maggots from the local fishing shop.. the other fish liked them, and the eel showed more interest in them than bloodworms, or anything else I'd been trying to feed him, and looked as if he was trying to eat one, he made a move towards it, but didn't get it in his mouth,,, so I'm not entirely convinced he's eaten too much since I got him.. (about 3 weeks ago) hope you can help.... Sami <This spiny eel is extremely mal-affected by a bacterial infection... though often termed fungal... A very quick administration of antibiotics to the system (Chloramphenicol if you can get it, Spectrogram (product) if not... at double dose... 250 mg. per five gallons, addition of a teaspoon of aquarium salt per five gallons... in a separate treatment system, attention to water quality while there... offering tubificid worms as food... Might save this specimen, but doubtful at this stage. Bob Fenner>

Sores on Aethiomastacembelus elipisfer   3/10/06 I just bought a Aethiomastacembelus elipisfer about a month and a half  ago.   This week I see a sore on its side.  Also, it is not very  active, preferring to "make like grass" in the plants.  I am not sure it has  been eating, but have fed guppies and will continue to do so. do you have  suggestions on treatment for these sores? Thanks Pei <Mmm, yes... from Oliver's input and mine posted on WWM (Please use the Google search tool or read here: http://wetwebmedia.com/FWSubWebIndex/spinyeelfaqs.htm These matters need to be addressed aggressively. Bob Fenner>

Fire Eel Issues - 04/05/2006 I have a fire eel (approximately eighteen inches) in a freshwater tank - think he might about 15 years old - not sure.   <Nice!> A couple weeks ago he stopped eating, became lethargic (not sure I spelled that right), <I believe you did.> and appeared to have labored breathing.  I dosed the tank with Maracyn II for five days, <Why?> and then another five days with Maracyn.   <Again, why?  Did you see symptoms of anything aside from the heavy breathing/lethargy?  Did you have reason to suspect a bacterial infection?> I have only used Mardel products on him including Coppersafe and occasionally Maroxy.   <.... should try not to use medications unless you know there's a disease that must be treated....> He has a couple injury sites that have turned white.   <Disturbing.  How did he become injured?  Tankmate squabble?  Escape attempt?> After the second week of antibiotic treatment, he improved, regained his appetite and was swimming like usual.  Last night, he stopped eating again.  I'm not sure what to do this time around.  I/m afraid he might be dying from old age?   <In all honesty, this is possible....> I am doing 20-25% partials every 5-7 days.   <Ammonia, nitrite, nitrate, pH readings?> He has a small area of whitish skin on the side of his face.  Please give me some suggestions. Linda Itoh Hello, I wrote to you a little earlier and I need to add a symptom I just noticed with my fire eel - his stomach is bloated.   <The bloated belly and refusal to eat are troubling....  I would first check (and correct, if necessary) his water quality....  Next, there are a number of things to consider.  First, simple constipation.  Foods high in roughage content may help with this (adult daphnia, adult brine shrimp....).  Secondly, these dropsical symptoms may indicate an internal bacterial infection; if that's the case, there may be little you can do, depending upon what, exactly, is troubling him.  You might consider trying to feed with an antibiotic medicated food, though this will (obviously) be difficult if the fellow refuses to eat....  Maintaining optimal water quality and hoping for the best with foods to help reduce constipation may be your best first start.> Linda Itoh <My best wishes to your eely friend,  -Sabrina>
Fire Eel Issues - II - 04/22/2006
I have not been doing well with my fire eel. His belly is still bloated and he is not eating.   <Yikes!> I have been doing water testing and the results as of last night were:  ph 7.5, copper .5 to 1.0, <I still don't understand what you are treating with the copper?  Our correspondences haven't let me to believe that you are dealing with ich or other parasites....> nitrite .09, <This should test as zero....  likely you need to do more frequent water changes right now; the copper has destroyed your biological filtration....  And again, why copper?> nitrate (I am still having problems figuring out) I am using tetra test NO3 and color in test-tube matches 25mg on color chart with kit; <Mm, it's in parts per million, no?> however if I divide that by 4.4 I believe  that number is 5.68,  is that good or not?   <You've lost me here; why are you dividing?  Is it not displayed as parts per million, or....?  And what about your ammonia readings?> I think he has an infection and needs to be treated with antibiotics.   <.... this is possible, but not seeing the fish, not having all the data, I really can't tell you what he might need at this point....  If you do suspect an internal bacterial infection, Kanamycin or Nitrofurazone in food is my recommendation....  or at least orally if not in food, if in any way possible.> I have only used Mardel products in the tank.  The white injury sites are from him trying to cram into a castle which is too small for him now which I have not taken out yet because he is so panic stricken when I work in the tank I'm afraid he is going to jump out. <If there is an item in the tank responsible for the injuries to the animal, PLEASE get it out of there IMMEDIATELY.  Replace it with more decor of a more desirable nature, large enough not to damage the poor fellow.  This is imperative; if he's getting wounds from this castle, it needs to go, pronto, in favor of something that won't wound him.> Some years ago I was working in the tank and he took off like a rocket right out of the tank, in the air, and landed on a tile floor.  He did recover but has not been the same since.   <Yeee-ikes!  I can imagine!  Sneaky little fellows....  give him more appropriate hiding spaces, things to make him feel secure, things that won't wound him.> I also have been using well water for the past 3.5 years which I treat with stresscoat when I partial.  Please give me some suggestions?   <This bloating and refusal to eat is hopefully something that can be passed....  I would add a tablespoon or two of Epsom salts (Magnesium Sulfate) per ten gallons of water; this may very well help him pass any blockage.  Secondly, I would absolutely quit with the copper, unless you are treating for ich or some such....  adding copper is shooting yourself in the foot right now, with regards to water quality.  If you are highly confidant of a bacterial infection, I would recommend treating with Kanamycin and/or Nitrofurazone, again, preferably orally and preferably in food.> Right now, I am just doing partials about every 4-5 days.   <You may need to increase this to *daily* with the copper in your tank destroying your biological filtration....  Be testing, *daily*, for ammonia, nitrite, nitrate, pH....> Thank you.  Linda <All the best to you, Linda, and don't get disheartened.  Spiny eels are resilient fellows, and hopefully yours, aged though he is, can pull through this.  Wishing you well,  -Sabrina>
Fire Eel Issues - III - 04/23/2006
Sabrina, thank you for your response with regard to my fire eel.   I had been treating the tank with copper because the injury sites were not healing like they have in the past.   <Copper really isn't very useful for aiding wounds in healing....> I did about a 30-35% water change yesterday and my copper level today is 0.5.  I plan on not adding anymore copper.  I was thinking if I maintain a therapeutic level of copper it would keep him from getting parasites.   <Mm, for the most part, you're not so likely to see parasite issues pop up unless you introduce them; it's bacterial complaints that you need to have concern over.> I have always maintained a level of copper in the tank for as long as I've had him. <With regards for parasite prevention, a more useful and less toxic substance to use is just aquarium salt.  Spiny eels don't much like it, but tolerate it FAR better than copper.> Today my nitrite is 0.3 mg/liter, and NO3 is 50mg/l.  I am using tetra tests with color charts measures reading in mg/l.   <I see.  mg/L is the same as ppm (parts per million).  Thus, you have .3ppm nitrite and 50ppm nitrate.  You most certainly need to do some hefty (or heftier) water changes; spiny eels don't appreciate high nitrates....  I would quickly strive to bring this much lower; 20ppm at a maximum, less if possible.> The only test chart I see with ppm's is the copper chart.  I am thinking I need to another partial today; but I just don't know.   <Yes, absolutely.> My ammonia  is 0 according to the tetra test color chart reading from 0 thru 5.0. <Get the nitrite to zero, and the nitrate down.> Interestingly, after I did the 30-35 partial he actually ate some food last night; <Ah!  Good!> but still looks very uncomfortable, and is still bloated. I thought the bloating was due to a bacterial infection which is why I'm thinking he needs antibiotic.  Can you tell me where I can Kanamycin in the oral form?   <You might have to mix it yourself, or take a look at http://flguppiesplus.safeshopper.com/234/cat234.htm?590 - they have an antibacterial medicated flake with Oxytetracycline, which might also be effective.> The only antibiotic I keep on hand are the Maracyns.   I did not put Epsom salts in the tank yesterday because of the partial and he seemed to have gotten some relief from it.   <The Epsom cannot cause him harm, even if he were in perfect health, and may help *immensely*.> I'm so distraught over the possibility of him not making it through this.   <Get the nitrate down....  Discontinue copper....  Add Epsom....  Maintain impeccable water quality (ammonia and nitrite at ZERO, nitrate less than 20ppm and preferably closer to 5ppm)....  Wait a few days, then begin with antibiotics in food if no improvement is seen.  At least, that's what I would do.> Thank you for your help.  -Linda <All the best to you,  -Sabrina>
Fire Eel Issues - IV - 05/13/2006
Hi Sabrina, <Hi, Linda!> I'm writing again with regard to my bloated fire eel.  He is hanging in there; but he is obviously not comfortable.  I added the Epsom and have discontinued the copper since April 25th no copper.  The copper level is holding at 0.25 ppm, <I continue to urge you to get this to zero.> 0 ammonia, 25 mg/l nitrates, <Really needs to be lower still.> <0.3> nitrites, <Needs to be zero. ph is holding at 8.   <Yikes!> I have read that fire eels like a lower ph so the 8 concerns me.   <Yes, me too, a great deal.> However, at this point I'm so frustrated with what to do, maybe the pH8 is not a significant problem.   <Mm, it is a problem, I think.  Many/most fishes are very tolerant of a wide-ish range of pH, but spiny eels really should not be in a pH this high.  Dangerous.> After our last email conversation he was not eating so I put Maracyn II in the tank for 10 days, he starts eating and swimming around.  He will not eat flake food, shrimp, bloodworms or earthworms.   <Disconcerting that he won't take worms....> He eats shrimp pellets and algae wafers.  Since I stopped the copper his welt-like blisters are getting white-ish and he is scraping along the bottom of the tank.   <Still signs of irritation, perhaps at the nitrite, nitrate, copper, or that very high pH - or something else in the water, even.> I have done partials every 2-4 days, however he seems really stressed after a partial.  I am on well water here and I did a hardness test on it - 14 dGH - and 13 dKH.   <Kinda high, there.> I have always used water right from the well, and am now wondering if I should be using water from the tap which is ran through a softener. The tap water reads 1dgh and 12 dKH. <I would advise against the softened tapwater; this can be even more trouble than it's worth.  The very hard, high pH of the current water, though, is troubling.  I would like to suggest that you try doing a couple of water changes (carefully, and spaced apart in time) with some water from a Reverse Osmosis filtration unit or even store-bought bottled water - I don't know where you are, but many places have water stores where you can fill up a 5g water jug for a buck or so with straight RO water.  Just BE CAUTIOUS of this, as the pH of the purified/bottled water will be much, much lower than the pH of the tank - you do NOT want to lower his pH too quickly.> My aquarium readings as of yesterday are 18dgh and 10 dKH. I had to have my husband help me with these tests. Very complicated for me.   <And very kind of your husband, too - thank him for me.> Seems like he has skin problems since we moved from city water to well water.   <Bingo....> I'm probably just grasping at straws at this stage.   <I very strongly feel that the bulk of this animal's problems are environmental.  I would actually hold of from medicating at all (aside from the Epsom salt, I would use that again after your next water change).  I would like to see this critter VERY slowly (as in, 0.2 a day) go down to below a 7.0 pH with as close to zero nitrate as possible (below 20ppm at the least), zero ammonia, zero nitrite, zero copper, and lower hardness with the use of RO/bottled water.  I really think a more accurate environment may be the whole key here.> I have purchased Maracyn Plus Biospheres Antibacterial (Sulfadimidine and Trimethoprin).  Do you think this would help with the skin welts?<Mm, I would hold off on medicating this animal any more than absolutely necessary at this point and see how an improved environment affects him.> Please give me your thoughts.   <You've got 'em now, and I hope they help some.> Thanks,  -Lyn <All the best to you and your eely buddy,  -Sabrina>

Fire Eel Issues - V - 05/15/2006
Hi Sabrina, <Hi, Linda!> I'm writing with an update on my fire eel.   After I read your last reply, I did a small partial - only five gallons of aquarium water - did I replace with store-bought bottled water.  I'd like to explain something to you that my husband explained to me before I give you the numbers.  I have been testing the PH with a tetra test kit that reads from 5,0 thru 10,0 and the aquarium water has been reading an 8,0.  He brought in the ph kit for our pool water that reads in tenths from 7.0 thru 8.0.  We tested the aquarium water (before small partial) to see if it matched my ph of 8.  It did not - it read 7.6.   <A big difference....  I would test this against another aquarium test kit, perhaps at your local store; many/most stores will test your water for you for free.> We did the partial and  the ph on the tetra kit read 7.5 and the pool kit read 7.4.   <This is a difference that could be charted up to human error....  is very close.> This was on May 14th.  Tonight, I just did the ph readings and they are unchanged.  The nitrites and nitrates are also unchanged.  The dGH is still 18 but the kH is down to 8.   <One last time.  Ammonia and Nitrite MUST be ZERO.  Nitrate MUST be as low as possible; below 20ppm at the least, preferably even at or below 5ppm for this sensitive animal.  These things aren't options, but criteria on which your eel's life hinges.  The pH is next in line of importance.> The magnum filter was clogging up pretty good so I changed that tonight.   <Likely a/the "source" of high nitrate in your tank.> My fire eel has stopped eating again - 3rd night in a row - since I stopped the Maracyn II - he has stopped eating.   <This could very well be coincidence, to be quite honest.  These animals can sometimes stop eating once in a while.> I feel like I need to treat him with something especially since he has stopped eating again. <Bob and I and a few other folks were just talking about this tendency in aquarists; a desire to throw a medication at a problem....  This is a very, very unfortunate tendency, and probably kills more organisms than it saves....  Granted, I do not know you or your pet, but I still feel that throwing medication at the fellow's condition when there are KNOWN problems with the water that must be corrected is folly.> What would be in the Maracyn II to make him eat?   <Can actually be coincidence.> I can't determine if he is breathing easier or not since the partial - I don't think so.  IF he starts to look worse and I decide to medicate him, would it be safe to use the Maracyn Plus Biospheres?   <I can't recommend either, to be honest.  Not until the water quality is rectified.  Fixing the water quality is *imperative*.> In your last reply, you had suggested doing a couple of water changes carefully spaced apart. <Mm, as far as spacing them apart, what I'm most concerned about is not decreasing the pH too quickly.> Do you think another water change should be done in the next day or two, or more towards the end of the week?   <I would say NOW, and urgently so, until that nitrate reading is down.> And, I'm thinking another 5 gallons of bottled water and 5-10 gallons well water.  By the way, with regard to CopperSafe - I was reviewing my emails with you guys and noticed the very first one a Bob Fenner replied to and I got the impression he was okay with using CopperSafe.  I was just wondering about the difference of opinion.   <I am actually sitting with him now, he's right next to me....  We've talked, and he does agree that maintaining copper on spiny eels is not a good idea.  They just don't do well with many medications.  If you like, a direct quote from his Mastacembelid article:  "Spiny eels don't respond well to toxic dye and metal medications."  http://www.wetwebmedia.com/FWSubWebIndex/matacembelids.htm .  I do believe he misunderstood that you had intended to use copper as a constant preventative in the water....  I believe, and I feel that he does too, that this is a bad idea.> Thank you for your reply - again.   Lyn <Please do go ahead and read over the article and the FAQs file linked to it, if you would....  hopefully you might find some other piece of insight that would be of help to you.  Wishing you well,  -Sabrina>

Fire "Eel", Eye Damage - 10/12/05 Hello <Good morning.> I hope you can help me to help my Fire Eel. When we were cleaning the tank 10 days ago, my eel got a fright and decided to have a 100mph swim round the tank!  <Yikes! Hopefully this system is not too small for him to feel secure....> I think he must have hurt himself as I have now noticed that his one eye is totally white (looks blind) and he has a patch above the eye which seems to be getting whiter by the day.  <Definitely a concern.... Probably did scratch/damage himself during his speedy stint about the tank.> He is also off his food, not having eaten for three days (very unusual for him).  <And not a good sign....> I have bought some Potassium Permanganate (Condy's crystals), but don't know if I can use this as he is 'scaleless' and I have been told to be careful of medications as not all are suitable for eels. <You are correct. Do not use this.... Very, very caustic - will more than likely kill the eel, and can be hazardous to deadly even on stronger fish.> Please help. I am worried about my fat boy! <Bob's recommendation (and I agree wholeheartedly) is to add aquarium salt (the stuff marketed for freshwater aquaria, not marine salt), perhaps at one or two tablespoons per ten gallons, possibly also add Maracyn I & II (erythromycin and Minocycline) as a preventative.... and of course, maintain optimal water quality. Try feeding stinky, attractive foods like bloodworms (live if you can get 'em) or even redworms/tiny earthworms you collect yourself from an area uncontaminated by pesticides/herbicides.> Thanks, -Wendy

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