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FAQs on Mastacembelid, Spiny Eel Foods/Feeding/Nutrition

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 SystemsSpiny Eel Disease, Spiny Eel Reproduction,
By Species: Fire Eels, Peacock Eels, Tire Track Eels,

Meaty, fresh to live... worms of all sorts irresistible

Fire Eel, fdg.        11/11/19
Hi Crew! Haven't stopped by for a while, but a question has come up and you've always been my source for the right/best answers.
<Ahh!>
I have a year old Fire Eel, about 8 - 10 inches long in great health, very friendly, good body weight, everything's good. I got this fish at 2 inches about this time last year and I've always fed it Hikari Blood worms, Tubifex worms, and the occasional shrimp from the grocery store. He/she will NOT eat beef heart, brine shrimp, or krill.
Recently, a fellow fish enthusiast has been brow beating me to start feeding him/her fresh fish from the grocery store. I have no problem with that, except for the old "if it ain't broke, don't fix it."
Also, I've read stories of people feeding fresh fish to young Fire Eels, causing them to grow too fast, overtaxing their bodies with too much protein, fouling their water, and eventually causing death. Is this true?
<Mmm; I do think that there can be danger in growing stock too quickly... Health, shortened lifespan issues>
If so, what would be the appropriate age/size to start feeding fresh fish?
<Fresh as in cut strips of muscle? IF small enough bits, at any size.
However, as you state, if the animal is happy, healthy w/ the current regimen... I would particularly skip beef heart. Bob Fenner>
*Renee *
Fire Eel         /Neale      11/13/19

Hi Crew! Haven't stopped by for a while, but a question has come up and you've always been my source for the right/best answers.
<Thanks for the kind words.>
I have a year old Fire Eel, about 8 - 10 inches long in great health, very friendly, good body weight, everything's good.
<Sounds like you should carry on doing precisely what you're doing now.>
I got this fish at 2 inches about this time last year and I've always fed it Hikari Blood worms, Tubifex worms, and the occasional shrimp from the grocery store.
<Sounds good. Usual reminder about Tubifex being a potential risk, and that shrimp are high in thiaminase, so as you say, use sparingly.>
He/she will NOT eat beef heart, brine shrimp, or krill.
<And neither will I! No big deal.>
Recently, a fellow fish enthusiast has been brow beating me to start feeding him/her fresh fish from the grocery store.
<If your Spiny Eel wants to eat some white fish fillet, provided such is thiaminase-free, then sure, go ahead. No live feeders, however.>
I have no problem with that, except for the old "if it ain't broke, don't fix it."
<Agreed; but as fish get bigger, chunkier meals made from less expensive foods, such as tilapia fillet, become more economical than aquarium shop blister packs of frozen invertebrates.>
Also, I've read stories of people feeding fresh fish to young Fire Eels, causing them to grow too fast, overtaxing their bodies with too much protein, fouling their water, and eventually causing death. Is this true?
<Overfeeding fatty foods can cause problems for fish, much as with humans.
But excess protein is eliminated as urea because the body cannot store amino acids, so while unlikely to "over tax" the body of the fish in any meaningful way, there is a connection between excess protein in the diet and poor water quality.>
If so, what would be the appropriate age/size to start feeding fresh fish?
<Try small offerings any time you want, and see what happens. Remove uneaten items. I'd suggest the old "wiggle on the end of long forceps" trick to entice your Spiny Eel, but however you're feeding frozen shrimp should work. Cheers, Neale.>

Peacock Eel, beh.; fdg.    8/22/18
I have a peacock Eel for roughly 8 months now. At first he hid all the time but now he is very active. Wondering if this is normal.
<Yes; this is normal behavior for spiny eels. Most are very shy initially, becoming more bold with acclimation, a dearth of bothersome tankmates>
I'm thinking he's hungry because he's out. And have been feeding him pretty much every day for the past 3 days and he comes to eat every time. Do I need to give him more at feeding times so he can go back to hiding. Or is he comfortable now?
<I gauge how fit fishes are as folks do in the fisheries industries; by apparent "girth" of the specimen. If it appears full, it is likely fine food-wise. Better by far not to over-feed; shortens life spans and presents
more maintenance>
Thank you much,
Jessica
<Thank you for sharing. Bob Fenner>

Fire eel frustrations !!  Fdg.       11/19/14
I have a fire eel that has been super healthy and active always. We have had him just under two years in which he has grown from 4" to about 16" and gained much in the way of girth.
Here is the issue.. I can not get the bugger to eat anything but frozen blood worms and live blackworms (I raise myself) I have tried withholding food for nearly two weeks, more than once, and I routinely offer prawn, night crawler, tilapia, krill, meal worms, snails and mysis shrimp. Eaten with gusto by his Ropefish and Bichir and Ctenopoma tank mates but never by him. He comes up to my hand and as soon as he sees it isn't bloodworms he goes in his cave and pouts.
Any suggestions? I am very concerned about his dietary needs. Any advice would be appreciated!
<I'd be worried too! Clearly he's okay if 2 years old, so there's no immediate worry. But do try live river shrimps, as most Fire Eels seem to love these. Earthworms should also be taken. Starving a healthy predatory fish like this for more than 2 weeks isn't a big deal, so feel free to do so. Also try soaking alternate foods in a defrosted cube of bloodworms.
Particularly earthworms as these are ideal, nutrient-rich foods for these fish. Sometimes chopping the earthworms into small bits helps if whole ones are too wriggly.
http://www.wetwebmedia.com/fwsubwebindex/spinyeelfdgfaqs.htm
Good luck, Neale.>

Fire Eel Feeding - 10/25/2012
Dear WWM,
<Hello, David.  Sabrina with you tonight.>
I bought a fire eel about 3 weeks ago.  It looked a little thin, about 8" long but otherwise was healthy and is now in a community tank with a 5"
tire-track eel and a few angelfish and other fish.  The fire eel hid for a few days then started to come out at feeding time, hanging about at the surface with the other eel at feeding time.  The tire-track eel eats any and every worm that it can get.  The new fire eel is clearly hungry and interested in the worms and tries to eat them but usually ends up spitting out even the smallest ones (or pieces of them) which usually get eaten by the other fish.  It almost looks like it can't swallow them (although it has eaten a few).  I'm thinking of: first, trying frozen food; or second, moving it into a small tank by itself for a few weeks to get it used to eating worms without competition and to fatten it up a bit. 
<I would actually do both of these things simultaneously.  If he was already "a little thin" when you got him three weeks ago, he's probably urgently in need of food by now, and needs some time without any food competition to get used to what and how you feed.  This is one of the less appreciated bonuses of quarantining new fish - getting it nice and fat and happy, used to your schedule and feeding regimen, before having to meet the rest of the tank and compete for food.  Quarantine: It's not just about disease any more!>
I'm concerned because I've never had problems getting spiny eels to take earthworms in the past.
<While you have him in a separate tank (you said "a small tank" - don't go too small, you don't want him to feel like he must escape and become eel jerky for you to find one morning), try a variety of foods.  You'll probably have best luck with frozen bloodworms.  Frozen Mysis shrimp would be a very worthwhile food (Piscine Energetics is my favorite brand by far).
 Try the earthworms again as he begins to get used to feeding time; make sure they're of an appropriate size for him.  Small "red worms", like little 3"-4" earthworms, would be good, I'd think.  Stay away from Tubificid worms; although Mastacembelids do eat them readily, it's just
not worth the significant disease risk that they can pose.>
Thoughts appreciated and thanks in advance,
<Get him off in a tank by himself to get used to the new fare, try other food options, and he'll be chowing down in no time.  I hope.  Once he takes food from you greedily, he's ready to re-join the main tank!  You might consider varying the diet of the tire track, too.  Frozen foods like bloodworms and Mysis, if he'll take them, will add to his diet very well. 
Although small worms (and large worms, when they get bigger) are a great food for spiny eels, most critters benefit from getting their nutrition from multiple sources.>
David.
<Best wishes to you,  -Sabrina>
Fire Eel Feeding - II - 10/29/2012

Hi Sabrina,
Many thanks for your quick reply.  I tried frozen bloodworms - both eels acted like I was trying to poison them
<Surprising!  Do try frozen Mysis, other options....  and keep at it with the earthworms.>
(other fish were happy though!).  The fire eel took a couple of pieces of earthworm this evening so I'll wait for a couple of days before moving it into its own tank - it's really trying, and the other thing is that there's a good chance we'll lose power in the next few days (eastern coast US) and I don't want to create too much disruption.
<Ahh, wise.  Best of luck - keep safe, okay?>
Cheers
David.
<Best wishes,  -Sabrina>

One-striped peacock spiny eel growth & feeding 4/15/12
Hello,
About 8 months ago I bought a one striped peacock eel (Macrognathus aral). As far as I can tell he's been fine all along; he's actually rather active and he's easily the most gluttonous fish in the tank.
<Good!>
One thing I've noticed is that perhaps he isn't growing as much as he should be. I can't really tell if he's really grown at all since I got him. Besides putting on some weight he hasn't really grown to be as large as I thought he should be. He's pretty much remained the same size in my eyes.
<Yes.>
Currently he's about 15cm, which is about 6 inches. He's in a 55 gallon tank with some common small fishes. I feed him earthworms which I get from the local angler store, since he doesn't really eat anything else I've tried.
<Earthworms are like crack cocaine to Spiny Eels…>
Frozen bloodworms he sniffs, but refuses to eat. Live bloodworms he does eat, but I stopped buying those. Doesn't eat live Artemia (brine shrimp?) either, nor does he eat any frozen food.
<Have you tried small bits of prawn and tilapia fillet? Mine always liked these.>
I do have a lot of earthworms, since he goes nuts over those, but I'm not sure that could be the reason he's not really growing? I thought they contained many nutrients & whatnot.
<Correct.>
He's also pretty much the only fish in the tank who can devour earthworms, so yes he's definitely receiving plenty of those.
Is this growth pattern 'normal'?
<Yes. Spiny Eels tend to be slow growers, and Macrognathus spp. especially. So long as he looks plump around the abdomen, don't worry too much.>
I know these guys should be able to become pretty large but I'm not quite seeing mine get there yet.
<He may well not grow much above 20, 25 cm -- while Macrognathus aral is said to reach 60 cm, I've never seen one that big.>
Thanks a lot
Kind regards,
Nigel
(I've attached a pic of my eel)
<Real nice. Cheers, Neale.>

Spiny eel... foods    2/10/12
I took a long time researching spiny eels (your links were very helpful)
however the only eels nearby are tire track, fire, and peacock the peacock looked like the one best for my tank but I don't have much experience feeding live food.
<They will take frozen foods like bloodworms and krill, but not freeze-dried foods or flake.>
if they can't be around Madagascar rainbows, bristle nose Pleco, banjo cats, or African butterfly fish can you tell me what fish would (I was looking for eel like bottom feeders but other oddball bottom feeders will be cool to)
<The problem is that almost all eels are difficult fish. If you don't have the right substrate, water chemistry, and/or foods for them, you probably can't keep them. They're also notorious escape-artists, whether we're talking about Spiny Eels, Ropefish, or any of the other traded eel-like fish. Horseface Loaches are moderately easy to keep if you have a large aquarium (55+ gallons) and a soft, sandy substrate. Kuhli Loaches are another option, but they are small (typically 8-10 cm when fully grown) and extremely shy unless you keep them in a big group (6 or more specimens). On the plus side, they're easy to feed and do well in the same soft, acidic water as most other community fish, and they won't compete much with catfish like Banjos or Corydoras provided you supply enough food for everyone in the aquarium.>
Thanks, Aaron
<Cheers, Neale.>

feeding my Half-Banded Spiny Eel 11/09/11
Hello I was wondering about my half-banded spiny eel. I hand feed my eel and I fed him Hikari Frozen Blood Worms and I feed him one cube because I have a 20 gallon tank. I usually feed him 3-4 days. Am I feeding him too much? Too little? Please help.
Luke
<Hello Luke. There are a couple of issues here. Firstly, there's competition from other fish. Provided your Spiny Eel is the ONLY bottom-feeding carnivore (i.e., there aren't any loaches or catfish) then you can be reasonably sure that your Spiny Eel is eating what you're putting out. The second issue is that bloodworms aren't enough for your Spiny Eel to live on. They don't contain much variety of nutrients. So, you need to be adding other small wet-frozen foods as well: krill, fortified brine shrimp, glassworms. You can also offer occasional live foods, particularly earthworms, as well as suitably small pieces of seafood and white fish fillet. The more variety, the better. So, with these two things in mind, the aim is to provide NIGHTLY meals sufficient to keep the Spiny Eel looking plump and healthy. It's really difficult to estimate the precise amount, but for an eel 15 cm/6 inches long, half a cube of bloodworms, or some similar-sized portion, would be about right. Adding some slow-moving scavenger, like a Whiptail Catfish, would be helpful if you're worried about leftovers. Whiptails are particularly good because they prefer sand substrates, which small Spiny Eels MUST have (gravel eventually damages, and subsequent infections frequently kill, small Spiny Eels). They also eat things like algae wafers that Spiny Eels won't eat, so you can ensure both species get enough to eat without problems. Cheers, Neale.>
Re: feeding my Half-Banded Spiny Eel   11/9/11

I have large pebbles in my aquarium. How should I add sand for my eel to burrow in?
Luke
<Doesn't really matter. Assuming you don't have an undergravel filter, you can easily remove the gravel and replace with smooth silica sand (e.g., what Americans call "pool filter sand") without needing to switch off the filter or remove the water. Use a net to scoop out the gravel. This is easiest and safest with the fish removed to a bucket, together with any delicate plants. You can leave the filter running. You don't have to remove every last bit of gravel, just most of it, i.e., 80% or more. In fact stirring in some gravel into the sand actually makes it look rather more realistic, especially if you add a few small water-worn pebbles too. Clean the sand very well before use! Add it into the tank gently, perhaps a jug or two at a time. There's bound to be some silt. Don't worry about this: it settles out within a couple days, quicker if you have a good filter, and "filter aid" drops help even more. Some scum will likely collect at the top of the water too. You can skim this off with a net. Anyway, add the sand to sufficient depth. If you don't have plants, then 2.5-5 cm/1-2 inches will be ample, banking the sand so it's deepest at the front, so dirt rolls forwards to the front where you can see and remove it easily. If you have plants, you can have a deeper bed. Do read:
http://www.wetwebmedia.com/fwsubwebindex/nicebottoms.htm
http://www.wetwebmedia.com/ca/volume_7/volume_7_1/dsb.html
Spiny Eels will plough through sand an inch or two deep, keeping it nice and clean, so don't worry too much about anaerobic decay. Sand can look a bit bright at first. It darkens with age, and if you have floating plants or plants with big leaves, overhead shade helps as well. Do be aware of the problems with sand. Sand can scratch glass if caught between a sponge and the glass; sand can get sucked into filters if the inlet is too close; and big fish, especially Plecs, are apt to send sand flying all over the place when the root about for food. On the other hand, virtually all bottom-dwelling fish prefer sand, including eels, catfish, loaches, and most cichlids. Cheers, Neale.>
Re: feeding my Half-Banded Spiny Eel   11/9/11
Thank you!
<Most welcome. Neale.>
Re: feeding my Half-Banded Spiny Eel
Won't that cloud my water?   11/9/11
Luke
<Read my e-mail again. All explained there! Cheers, Neale.>
Re: feeding my Half-Banded Spiny Eel  11/11/11

Thank you very much for all your hard work and time.
Luke
<Most welcome! Neale.>

Striped Peacock Eel black edge on tail   10/6.5/11
Hello,
<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.
<Good>
Thanks for your help, I'm just wondering if I should start getting worried or not.
Kind regards,
Nigel
<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

Hello,
<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.
<Ok>
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!
Nigel
<Mmm, do read here as well: http://wetwebmedia.com/FWSubWebIndex/spinyeelfdgfaqs.htm
BobF>

Question About Fire Eel Diet   3/21/11
Hello, I bought a 10" Fire Eel on Tuesday. (Today is Sunday.) Until yesterday, I tried feeding her frozen bloodworms in a cube but she paid no heed to them. Today I went and bought freeze-dried krill. After holding the piece of krill in front of her for fifteen minutes, she finally lunged forward and ate the krill. She munched on it for a few seconds, then spat it out, then ate it again, then spat it out again. After about twenty tries, she gave up and left the krill. What should I do? And any suggestions on hand-feeding?
-Sherry
<Try using earthworms. Fire Eels love them. Set up a composter if you don't have a clean (no pesticides!) garden to collect them from. Bait shops may sell them too. Once settled -- which can take a couple of weeks -- Fire Eels do well on a diet of earthworms, strips of thiaminase-free seafood (tilapia fillet, cockles), and live river shrimp. They will usually eat prawns too, but these contain thiaminase, so use sparingly. Wet-frozen bloodworms and krill are taken as well. Don't waste your time with freeze-dried foods. Do review tank conditions, e.g., no other bottom feeders should be kept with them, and the substrate MUST be smooth sand or fine, smooth gravel. Fire Eels are among those species that aquarists regularly kill; they are very, very demanding and not for beginners. Do read:
http://www.wetwebmedia.com/fwsubwebindex/matacembelids.htm
Cheers, Neale.>

Re: Flower Pattern eel - What kind of Spiny eel? Fdg. "Tiger" Bumble bee gobies ID, Neale    4/5/10
Bob, thanks for the website. Unfortunately I wasn't able to make a 100% positive identification from there, no biggie. To me he looks like a big zig zag eel, but I always thought they were the smallest of the spiny eels.
<There are at least four species of Mastacembelids commonly labeled as such>
He looks a little bigger than most zig zags I've ever seen. I'll keep watching and make sure he doesn't out grow his home. Maybe if I can snap a good picture of him sometime I'll send it in, he is not a very colorful fellow nor does he have an elaborate pattern so it is hard to find any distinguishable markings to compare with. He's very brown with some black markings along the top half of his body all the way back. Tough to ID with some of the small and black and white photos they have.
I do have a few other question if you don't mind. I feed both my eels mainly earth worms. About a 1/4 to a half inch piece once or twice a week.
I've read spiny eels "reuse" their food and don't have to eat for 2 weeks sometimes.
<Mmm, ones in good condition, health, can go this long w/o eating... but better to offer food every other day at least>
What kind of schedule do you recommend. They look very healthy and have never seemed too thin or overly bulging so I figure I am doing good. What else should be a staple in their diets?
<Please read here:
http://wetwebmedia.com/FWSubWebIndex/spinyeelfdgfaqs.htm

Tire track eel (sys., fdg. reading), Trichogaster microlepis questions 01/30/10
Hello, I've recently purchased a Tire track eel (Mastacembelus armatus) and a very large (quite beautiful) Moonlight Gourami (Trichogaster microlepis) from my LFS, and added them to my main tank, which currently has six small silver dollars, a Black ghost knife, a Leopard Ctenopoma, a large Rhino Pleco and two Botia Kubotai inhabiting it. After adding them, they all seem to be getting along very well, the Botias chasing the eel a few times, but nothing more than that. Since the Gourami is the only inhabitant of the upper regions of my tank, it's not being bothered by anyone. The eel is wonderful, swimming around the tank, looking though thru glass at us, and so on. The only problem is, he likes to play in the filter. He swims up into the filters
<? The intake/s and discharge are not screened?>
that hook on to the back of the tank, stays there for a while, and then slowly swims out when he decides to. Now, since he doesn't seem to be getting hurt, I don't mind-- I'm just worried that he might think he's ging
<?>
into the filter, but really be going over the back of the tank. I'm trying to find something to cover the back of it, but until then, he's at risk of climbing out
<A very common issue/problem with captive Mastacembelids>
(I should have eel-proofed my tank before I got him).
<Yes. Cover all openings now>
What I'm actually asking though, is what diet is best for them-- Would a diet of frozen bloodworms, flake, shrimp pellets, and occasionally live brine shrimp/guppy fry suffice?
<Read here: http://wetwebmedia.com/FWSubWebIndex/spinyeelfdgfaqs.htm>
I know they can be timid while feeding around more aggressive fish, so I I'll be using the turkey baster. Also,
will the Gourami get along with a Butterfly fish?
<Maybe... depends mainly on the size of the system>
The surface area of my tank is quite large, with ample floating plants, and the Gourami doesn't usually stay at the very top of the tank where the Butterfly fish would be (would have got the butterfly instead, but my reserved specimen at my LFS had a fungal infection yesterday, waiting for a new shipment...). Thanks! -Jack
<Welcome. Bob Fenner>

Mastacembelus erythrotaenia... beh./fdg... comp. with their own kind   9/27/09
hey Guys pls help cause I love my eels
Ok. It's been a year now since I had my fire eels in a 65g tank(by the end of the month I will move them to my newly built 400g tank in my apt) The bigger one(around 16'' is thriving in my tank and he eats well e.t.c and has grown a lot since I bought him. As for my second one, it's a bit smaller(around 14'' and thinner) has stop eating earthworms or shrimps from my hand . It's been 3 weeks since he was eating from my hands and generally since then he's been acting very strange and I hereby fear the worst. He hasn't eaten anything for 3 weeks now and has started to get thinner, the food goes in front of him and he's scared and won't even smell it and last but not least he's started doing some speed laps around the tank and sometimes he even crashes on the tanks walls or the driftwood e.t.c. No visible fungus or fin rot or anything. On the outside he seems quite healthy. What can I do to save my little buddy? Any suggestions on what he may be having fellas? Please help me...:o(
<Greetings. The short answer is that the larger Spiny Eels of the genus Mastacembelus are rarely sociable (unlike their smaller, more gregarious Macrognathus relatives) and it's entirely possible the bigger of your specimens is bullying the smaller. Once moved to a larger aquarium, this problem may solve itself, especially if each Spiny Eel has a suitable home, such as a clay pipe, at opposite ends of the aquarium. But I wouldn't bank on this being the case! Mastacembelus erythrotaenia is, like all Spiny Eels, sensitive to bacterial infections for reasons not altogether clear.
Scratches and other types of physical damage often serve as starting points of such infections. Gravel, as opposed to sand, substrates seem to exacerbate this when the Spiny Eels are small. The addition of a small amount of tonic salt to the water apparently helps; Baensch recommends 1-2 level teaspoons per 2.5 US gallons. If you suspect a bacterial infection, prompt treatment with an antibiotic such as Erythromycin may be helpful. Do read here for more:
http://www.wetwebmedia.com/FWsubwebindex/spinyeelsmonk.htm
Cheers, Neale.>

Re: Mastacembelus erythrotaenia  9/27/09
Thank you so much for you super prompt i really appreciate it. As i said , no visible scratches or signs on the boy, last night i put an earthwork wiggling in front of his nose and he didn't even pay attention!
<This is why I suspect the problem might be psychological rather than merely physiological. Move the smaller Spiny Eel into another aquarium, and see if it starts feeding again.>
He just went away. I started today some MARACYN II treatment from Mardel because i can only suspect internal parasites or infection. Is the Maracyn II ok for this kind of treatment?
<I honestly don't think the problem is bacterial. If there aren't any symptoms of bacterial infection, then there is no particular reason to add an antibiotic.>
Thank you guys you're doing an excellent type of work here, i really admire you guys!
<Kind of you to say so. Cheers, Neale.>

Re: Mastacembelus erythrotaenia 9/29/2009
What are the symptoms of a bacterial infection by the way if i may ask?:o)
<On Spiny Eels, the most common signs are first excessive amounts of white mucous on the skin, then bloody sores on the skin and fins, lethargy, and then eventually death. Spiny Eels can of course get the other bacterial problems that other fish get: Finrot, Columnaris, Dropsy, etc.>
And as for the eels living together, it's been 7 months now since i got them and they never had a problem or bite one another, or chase or whatever.
<Sure... when they're young, they're gregarious. Once sexually mature, that's when the problems begin. Much like any other territorial fish.>
And what about the speed laps around the tank?
<Certainly a possibility.>
I was watching the whole thing, the bigger eel was in it's pipe and the smaller one was acting like crazy hitting the tanks walls and the driftwood e.t.c. That why i am a bit fuzzed.
<I'm not phased at all. Mastacembelus erythrotaenia is well known to be intolerant of its own species under aquarium conditions.>
Sorry for bothering you guys...
<Cheers, Neale.>

Mastacembelus erythrotaenia; diet; health - 7/16/09
Hi
<Hello,>
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.
http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm
>
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.
http://www.wetwebmedia.com/FWSubWebIndex/spinyeelsmonk.htm
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.
Kristal
<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.
<Good.>
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.>
Thanks.
<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.
<Indeed.>
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.>

Fire eel, fdg., hlth.  6/6/09
Hello my name is Crystal
<Hello,>
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:
http://www.wetwebmedia.com/FWSubWebIndex/spinyeelsmonk.htm
Cheers, Neale.>

Striped peacock eel 09/04/08 Hey, <Hello.> My name is Brodie, I just purchased a striped peacock eel from my local fish store. My water in my 20 gallon long tank is sitting at about 78-79 degrees, and it has a rock cave, some plants, and a piece of drift wood. So from my research the tank has plenty of the dark hiding spaces striped peacock eels prefer. <Okay. What about the substrate? Spiny eels need sand or small rounded gravel. In addition it would be good if the rocks had no sharp edges.> After I acclimated him to the water he immediately dove down into the rocks, which I read would happen if the tank is too cold, <no> but it's at the recommended temperature. Also he looks to be a little under nourished, I think the store was feeding them fish flakes. I read I can force feed him blood worms through an eye dropper, and this will replenish his health into a sociable tank mate. <I would not do that too much stress.> In the tank as well are 5 tiger barbs which I read do fairly well with the striped peacock eel. <This tank will be overstocked in my opinion once your fish are grown.> I would like to know if you think him burring himself in the rocks right away is a reaction to being in a new tank, <Yes.> the other fish, or because he isn't healthy from the pet store? Also I would like to know if the force feeding is a good idea? If not, what might I try to get the little guy up and running like he is supposed to act? <As food try feeding at night when the barbs are asleep and the eel feels more safe. In the beginning they are almost always nocturnal, which can change with time and patience. Bloodworms and live earthworms (nightcrawlers) of adequate from a toxin free garden would be a good choice of food items to start with. The small earthworms can be fed with tweezers, just dont stress the animal too much. Please read http://www.wetwebmedia.com/FWsubwebindex/matacembelids.htm (including the linked FAQs on top of this page) and http://www.wetwebmedia.com/FWsubwebindex/spinyeelsmonk.htm and http://www.wetwebmedia.com/ca/volume_4/V4I3/Spiny_Eels/Spiny%20Eels.htm.> Thanks for your help. <Welcome. Marco.>

Re: Striped Peacock Eel   9/6/08 Thanks for the information. <Welcome.> I have the small round gravel in the tank, and the eel went right after the blood worm I cut for him. <Glad to hear. I guess the feeding issue is solved.> I have an old 29 gallon tank I can set up for the eel or the tiger barbs when overcrowding due to the growth of the fish occurs. <Very good. Have fun with your new pet. Marco.>

Fire eel not eating. 01/08/2008 I recently acquired a 8 inch fire eel from the LFS. <Ah, a beautiful fish. But not easy to keep; indeed, one of the most challenging of all the freshwater fishes. Make sure you read the several articles we have on this family of fish here at WWM, including: http://www.wetwebmedia.com/FWSubWebIndex/matacembelids.htm http://www.wetwebmedia.com/ca/volume_4/V4I3/Spiny_Eels/Spiny%20Eels.htm http://www.wetwebmedia.com/FWSubWebIndex/spinyeelsmonk.htm And then follow the links to related articles.> I've had it about 4 weeks now and as far as im aware it hasn't eaten since I brought it home. <Unfortunately this is very common. There are several issues behind this. The first is that these fish are easily spooked. Stick them in a new tank, especially one with busy or aggressive fish, and they get scared. Small specimens, such as yours, are obligate burrowers, and must be kept in tanks with a sandy or muddy substrate; a lot of people try to keep them in tanks with gravel, but they eventually end up with dead Spiny Eels. So make sure you are using a fine, lime-free sand such as silica sand. Finally, Spiny Eels are fussy feeders. Wild fish basically only take live food, and that needs to be things like river shrimps and earthworms. Do not use feeder fish! Spiny Eels are simply far too sensitive to bacterial infections.> Water param.s are fine. <Define "fine". For Spiny Eels, water chemistry admittedly isn't critical, but you do want to avoid very acidic or very basic conditions. Neutral, moderately hard water is likely the idea. Historically people have kept Spiny Eels in slightly brackish water, but they certainly don't need salt. What salt might help with is in inhibiting protozoal and fungal infections.> Ammonia and nitrites are both at 0 and nitrates on the tank its in stay below 10ppm. Water is a steady 80. <A little on the warm side; unless you have specific reasons to do otherwise, aim for 25C/77F so you get as much oxygen in the water as possible without compromising the health of the fish.> I've tried feeding him Frozen brine, Mysis shrimp, Krill, Bloodworms, White worms, HBH super soft and HBH shrimp pellets, Hikari carnivore pellets, and live earthworms. <Earthworms are good, and should be taken. You might also try live river shrimp and clean (i.e., home-bred) livebearer fry.> He sometimes sniffs at the food but is never observed eating anything at all. <He will not feed during the day time, remember that. Spiny Eels are nocturnal predators. They also feed almost entirely by rooting about in the sand (that's what their special snout is for). So if you put a small quantity of bloodworms or earthworms in the tank at night, he will eat them if left alone. Obviously, you CANNOT keep spiny eels alongside catfish or loaches -- they will eat the food first! The Spiny Eel should be kept as the ONLY bottom feeder and the ONLY nocturnal fish in ANY community. This point cannot be stressed strongly enough. Virtually all Spiny Eel deaths come from three things: starvation, leaping out the tank, and bacterial skin infections caused by gravel.> Im at wits end because I know its not going to be much longer before he croaks from starvation. <I agree, you are in a critical situation. But follow these rules and read those articles and you'll be doing all the right things.> Any help or advice tips would be greatly appreciated. <Good luck, Neale.>

Spiny eel system and food 05/31/07 Hi there! I found your site yesterday and have read about every page in it by now! Very informative, thank you! <Hi Tori. Im glad you like the site. You really read every page? By the way, it's good you collect information before buying.> My sister knows how much I love fish and so for my birthday gave me a five gallon tank with a filter and a picture of a spiny eel that she wanted to get me. I've just gotten around to setting up the tank (it's been running for two days now, with Watersafe) and I just added three artificial plants (is this okay since they will uproot them anyways?) and a cave structure, but when I asked about the fish themselves I was very disappointed to hear that they've only been fed normal fish flakes and been left to eat scraps that fall to the bottom, and most of the eels in the tank seem very lethargic. <Probably starving.> Are these eels likely to survive very long? <When they eat again: yes. If you think about buying one insist that you want to see them eat. Probably theyll only eat live food, if you are lucky theyll eat frozen food. If they do not eat, have skin diseases or stay lethargic leave them there.> Are they worth getting or should I look around for better cared for eels? Also, if I get them, will they take right away to food like freeze-dried bloodworms and such? <Youll probably have to start with living worms and hope that they start accepting frozen food one day. Most of mine never did. Freeze-dried food and flakes will not be eaten by most spiny eels.> I haven't found live worms anywhere yet, except fishing worms, but I'm a little afraid of the bacteria that may be on them, especially just starting out. <Earthworms or nightcrawlers from toxin safe soil are ok, too.> The pet stores around here seem to carry only freeze dried worms, but what is the best? (the eels are small, less than 5 inches). <All dried foods are most often not eaten by spiny eels.> Also, since it's a small tank (5 gallons), is it going to be too crowded with more than one eel or one eel and another fish or two? It'd be nice to have something to look at while my eel is hiding. <First you need to know exactly what spiny eel species you are talking about. Some only reach 5 inches, others 3 feet. For even the smallest species I consider 15 gallons per specimen is the minimum. See http://www.wetwebmedia.com/FWSubWebIndex/matacembelids.htm and http://www.wetwebmedia.com/ca/volume_4/V4I3/SpinyEels/Spiny%20Eels.htm for more information. If you want to use the 5 gallon tank, itd be best to consider some other fish species.> Thanks so much! Tori. <You are welcome. Marco.>

Feeding A Fire Eel    11/28/06 Hi, my name is Joe St. Georges and first of all I want to say that your site has helped me greatly. <Thank you for your kind words.> I have a 75 gallon tank with a 7" or 8" fire eel, a 5" clown knife (I know I will have to remove him once he grows a little bigger) 2 2" silver dollars, 2 2" gouramis and a 5" short billed gar, and a few mini guppies for the knife and the gar (hopefully one day the eel!!).  I put two half drainage pipes in there, which the eels love to stay between them.  My question is that the gourami's are eating the blood worms that I feed the eel (I don't really ever see the eel eat but he stays plump).  I have also tried brine shrimp which he does not eat because they float and also red wigglers which burry themselves far under the gravel and I think out of reach for the eel. Is there anything else he might eat or a way of feeding him that others will not compete for.  I wanted to try ghost shrimp but and having a hard time finding them anywhere in Knoxville TN.  Any suggestions or advice would be great. Thank you Very Much, Joe St. Georges <Get some plastic feeder tongs used to feed reptiles. Put a small earthworm in the end of the tongs and slowly place the worm in front of the eel. The eel will be attracted to the worm and eat out of the tongs. These eels become very friendly and will take all kinds of food out of your hands. After awhile he will come to the surface when you approach the tank to let you know he wants to be fed. They can get up to 4 feet long!-Chuck>

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

Is my eel retarded or just lazy? Mastacembelid fdg.  8/2/06 I know eels are near-sighted, but how about retarded? <Some appear to do things that are none too bright...> Unless he is doing all his eating when it's pitch black, he's not eating.  Yes, I know they are nocturnal. <Mmm, not altogether...> By the way, he is a fire eel.   <Most mastacembelids are to a degree active by day> The first few days he ate like a madman.  Now, he takes the krill in his mouth, "chews" for a couple seconds, then spits it out, maybe does it a second time, and then he lets it float away. <... may no longer be "so hot" for krill...> I thought maybe the pieces are too big so I tried smaller pieces, like an 1/8 of an inch, and it's the same thing.  I've got live black worms too. <Irresistible> I have no clue if he's eating those, but at least the Corys and the clown loaches are.   <Oh yes!> He seems real interested when I put them in the water, but I haven't seen him eat any before they bury themselves.  He's making me crazy. The eel is about 8 inches long and my water parameters have been corrected to less than 20 ppm nitrate, 0 ammonia, 0 nitrate, 6.8 pH and kH of 2. <Looks good> Any suggestions or guidelines for eel behavior are appreciated.  I've heard they can go on hunger strikes.  I just don't know why he ate so well the first few days and now it's like trying to feed a spoiled 2 year old child. Sincerely, Steve <Have recently "split up" the Spiny Eel FAQs... Please read here: http://wetwebmedia.com/FWSubWebIndex/matacembelids.htm and the linked files above. Bob Fenner> Hello (Eel? Food, Freshwater?) We live in Iceland, and just purchased a few fish, and an Eel. My questions is, will the eel eat regular fish food? We tried asking the lady who owns the place, but being American over here is a slight problem :) any help would be appreciated. Thanks, Nicole Hatfield <Mmm, depends on what you mean by "regular fish food" and what sort of Eel this is. Please give a read over our site: http://www.wetwebmedia.com/ or use the Google search tool at the bottom of the homepage there... re this issue... Is it a freshwater eel? Do you know more specifically what kind? I have been to Iceland to visit... the local folks take a while to "warm" to new folks, but are genuine, honest people, as you will see. Bob Fenner>

Re: Eel Feeding <Anthony Calfo with the follow up, my friend> Hey, I couldn't get a good pic of him.....I haven't seen him eat any of the flake food, but not exactly sure where to get more meaty food for him either....at least, not around here.  <fresh seafood if unprocessed will be quite fine from the grocery store. Frozen is better than fresh for safety (pathogen transmission). Squid/Calamari is popular fare for most eels. Shell-on shrimp (even better with legs, head and innards) is also an excellent source of protein and good for keeping teeth worn. Resist fatty (oil) fishes for tank water quality. As a rule, crustacea are better fed to eels than fishes. And whole fishes (guts and head) are better than fillets.> I do however think he helped to kill our algae eater. Not positive about that though.  <wouldn't be a surprise> Will do what I can, and will try to find a pic of him tomorrow. Thanks again for all your help. Nicole Hatfield <do look through the photo archives of eels on www.fishbase.org if a picture is not convenient for you. Best regards, Anthony>

Re: hello, Iceland Eel Yes, I do love it here, but still not sure about the people :) and yes, all of her fish are freshwater fish. He is probably 2 inches long, and all brown in color. The pet shop owner gave me the flake fish food. She said it was for all types of fish. I have no idea what kind of eel he is. And I can't find a pic of him anywhere. I wasn't sure who else to ask, and from your website, you looked to be my man. If you want, I can catch him, and take a pic with our digital, if that will help any. Let me know, and thanks for all your help :) Nicole Hatfield <Please do send an image along. Does the fish seem at all interested in the prepared food you have? You will likely need to offer something more meaty... There are several choices here. Let's try to get a handle on the type of fish this is. Bob Fenner>

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>

Fire eel diet Hello, I have been reading your website for a while, it's wonderfully informational. I purchased a Fire eel a while ago.  She is now about a foot long and is living in an over turned decoration for her own personal cave. Her half of the aquarium is covered in a healthy layer (4") of black moon sand, to not scrap her belly if she ever decides she wants to burrow.  The tank mates are 3 fire red dwarf Gouramis, 2 Opaline Gouramis, and an angel fish.  The eel loves ghost shrimp, can't seem to feed her enough, but my pet stores can't seem to keep up with just my purchases per week. Two Eel questions: (1)   Feeding:  What consists of a good healthy eel diet?  What are all my options? <Many things... ideally natural food items like worms (including earthworms, grubs (larval beetles) like mealworms, ghost/glass shrimp... small bits of cut meats, fish flesh> How can I keep my eel healthy and full but not break the bank? <Culture (not you! the food)... and collection in the wild. Do look into growing night crawlers, meal worms et al.> How much of these options should I feed her? <At a foot in length... maybe every other day, enough food to where the fish appears "full"... not bulging>   Should I stock a smaller aquarium of just shrimp or something for her and feed her daily like the other tank mates or keep her on a feast a week schedule (I understand that's more like what their natural feeding habits are)? <Better to not feed too frequently or too much... (2) Future:  Ideally or acceptably, what size tank should she be in when she is full grown? <This may come as quite a shock... but a few hundred gallons. Take a look on fishbase.org re this mastacembelid species... It does get quite large eventually. Bob Fenner>

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>

Earthworms 'N' Eels - 03/07/2006 This is just a note for those eel lovers or those wanting to embrace the eel so to speak.   <.... I might pet one, but hugging is maybe not quite in my plans.> A couple of years ago I bought 4 eels for my hundred gallon aquarium.  Two fire eels and two tire track.  Sadly someone left the lid on the tank askew and I lost one a couple of weeks ago.   <Aww!  So sorry to hear this!> It was about 18 inches long.  I still have three left that are about that size, one is a good 23 inches long.  They share the aquarium with a sun catfish, a drift wood cat, a tiny (but extremely swift) zebra loach, a very fat clown loach which I bought at the same time (he's a good 10 inches long) a spotted perch, a dojo and a pair of spotted catfish that act like they're on crack.  I love my eels but let future eel owners be warned, they'll eat you out of house and home.  They pick at flake food in the morning, ah but at night they go through 3 of the large cubes of frozen blood worms  and whine for more.  I'm thinking that someday in the future I will find just one very enormous eel in that tank, all other fish having become snacks.  Do you know if eels might eat fishing worms?   <Yep.  Especially at that size.  I recommend culturing your own, to be sure they are in good health and nutrition.  Google "vermiculture".  You can start with worms in your own yard, provided you haven't used any pesticides, herbicides, etc.> I'm curious but haven't tried offering any.   <I'm sure they'd love 'em.  Try small worms, not big fat Nightcrawlers.> I was kind of hoping that the larger worms might just fill the tanks up a bit quicker.  Luckily I can say that none of them have had an ailment in the years I've had them. (knock on wood) and I don't want to encourage anything a live food might bring in.   <Agreed.> So if you have any information on earthworms for eels please let me know.  It would be much appreciated.    <I say give it a try - I've seen even smallish (<8" or so) spiny eels take small worms.> Thanks Jo <All the best to you,  -Sabrina>

Striped peacock eel info   3/16/06 Dear Robert, I am new to eel care and have some questions regarding eel behavior.  My eel is approximately 6-8 in long (I'm not sure exactly because he doesn't stay still) and appears to be healthy.  I have only had him a few days and he still looks pretty nervous about his new home. <Typical> I have a 55 gallon aquarium with 1TB aquarium salt for every 5 gal.  I am unsure about this but have read they do ok in brackish aquariums. <To an extent, yes> My main question is that could my 6-8 in eel eat a 3.5 in Senegal bichir or 5 in violet goby? <No, could not>   My bichir is terrified of my eel and the violet goby is MIA at the moment.   <The latter may have "jumped out"... look about on the floor... or be hiding.> Also I am unsure he is getting enough to eat I have tried fresh raw fish, cut Nightcrawlers, and shrimp pellets.   I have heard and read that these are all foods accepted by eels but I am nervous anyway.   <Best to offer some live worms, insect larvae that sink...> would a sort of community feeding spot work? <Mmm, could> None of my other fish are terribly voracious and I was thinking of a watering hole type situation.   If you could help to unravel some of this I would appreciate it. Sincerely, Matt Tompkins <I do hope your livestock all settle-in... they should be compatible... that is, "get along" with another. I would not add any more salt than you mention... and would try black worms, tubificids for your mastacembelid eel for now. Bob Fenner>

Fire Eel fdg., sys./comp.   4/1/06 Hi Crew! <Michael> Hope all is well in Wet Web land. I have a feeding issue with my 12" Fire Eel.  I purchased him 8 days ago from my LFS and since then I have not been able to get (him or her) to eat. <Happens... mastacembelids don't like changes... and being "moved" is a biggie> (We will assume its a he).............  I have tried feeding him frozen bloodworms with no luck and have just tried frozen krill even though I could not find any documentation supporting krill to feed him. <Some will take... but takes training on to> He is in a 94 gallon corner tank with plenty of caves housed with a red empress, Hap Ali, sunshine peacock, yellow lab, pike cichlid, <These are aggressive species...> and 2 cats (4" and not sure the type).  All fish are between 4-5 inches.   I understand that there is some good competition for food for him and have found ways around that.  I have tried using a feeding stick to spear the krill and have used the stick which acts like a turkey baster as well to blow the bloodworms by him.  He has had ample time to eat both.  My latest attempt today was to put the bloodworms in a shot glass and to lay the glass in the tank (and yes, I took the Jack Daniels out of the shot glass first). <Heee, good idea to both> The bloodworms stayed in the glass and the cichlids left the food alone.  I left that in there for a half hour and watch patiently to see him not eat. I have read and re-read your archives and understand that they can go on hunger strikes for weeks at a time but I guess I would really value your input on my situation. Aside from not eating he does look healthy and acts fine. Thank you in advance for your assistance! Michael J. Bukosky <I would try some live worms... likely "black Tubifex" if you could find, or other... placed in a container as you've done here... but really, the best scenario is going to be to place this fish in a less-agonistic setting... completely covered top, with "soft" rounded substrate, diffuse lighting and soft/er, more acidic water than some of the fish you list prefer. I would do this move if this spiny eel does not feed within another week. Bob Fenner> Some Questions about Spiny Eels - 05/22/06 Hi, <<Hello>> First off your site is very helpful and I have learned much from it. <<Is good to hear>> However I do have a problem that I couldnt find an answer to on Google or your site. <<Okay, let's see if I can help>> Im new to aquariums and about 5 weeks ago I purchased a Striped Peacock Eel. <<Read here and at the links in blue:   http://www.wetwebmedia.com/FWSubWebIndex/matacembelids.htm >> At first he didnt eat much (actually hardly at all) but a couple of weeks back he decided to eat as much as he could get.  I would like to know how many 8-10 mm long pieces of earthworms an eel about 7-8 inches should safely consume each day. <<Hmm...would think at least 3-4 pieces would be fine.  Live Blood and Tubifex worms would be relished as well, and will add some variety to the diet>> Also he is outgrowing his home/cave rather rapidly <<Indeed, can reach a foot in length>> so should I try to find him a new hideout (the gravel is a bit to harsh for burrowing) or attempt to possibly put new finer gravel in his half of the tank (during a partial perhaps?). <<I kept some of these eels a few decades back (did I really just say that?!), quite interesting creatures as I recall.  A fine/soft substrate is best/ideal...along with some plants/hiding places...and subdued lighting>> I want your personal opinion/s as well a reasonable answer/s so that is another cause to actually Email you guys and gals. <<No worries mate...I hope I've been helpful>> Thanks in advance, Matt <<Regards, EricR>>

Some Questions about Spiny Eels II - 05/23/06 Wow thank you very much. <<Quite welcome>> I was feeding him as much as 8 pieces and before I decided enough was enough and he still wanted more lol. <<Yes, can be quite glutinous.  Best to feed smaller portions several times a day>> However I know they like to hide and that they like "soft" substrate, I wanted to know if it would be a good idea to change part or even all of the substrate during a partial water change or add a larger hiding spot. <<Would depend much on your filtration setup...but I think changing out parts of the substrate with partial water changes over the course of a week or so would be safest>> Thanks again, Matt <<Always welcome, EricR>>

Unhappy Fire Eel  7/28/06 Hello,   <Hi Steve, Pufferpunk here> I'm glad I found this site and I hope you can help me.   <I'll certainly try!> I bought a Fire Eel about a week ago.  He is about 8 inches long. He ate very heartily the first 3 days I had him (hand fed frozen krill) but now hasn't eaten for the last 2 days.  He also seems less like a healthy eel.  What I mean by that is that in the beginning, his head was always sticking out of his cave, now he won't stick his head out at all.   <That pointy nose of his is for digging in the substrate for worms.  Try live blackworms to get him interested.  He will also eat bloodworms & eventually large night crawlers. > My ammonia and nitrite are 0 and my nitrate is about 80 ppm.  I know that is too high and will probably begin doing water changes twice a week at least.   <Woah!  No "probably" about that!  I'd do 25% daily (starting today), till they're down <20.  After that, 50% weekly is recommended.  Be sure to clean up any dead plant material & be sure to clean every inch of the substrate, especially under decor.> I also have a problem with my water turning soft, thereby my pH drops.  I have driftwood in the tank because my Plecos need it and I was told this would continue to make the water soft.   <Stick to soft water-loving fish then, like the Plecos & your fire eel.  Angelfish, rams & lots of other neat fish like soft water too.> About every 3 days I add pH stable which raises the water hardness and also the pH as a side effect.  Currently, pH is about 7.2 and KH is about 3.  None of my fish are aggressive so that is not an issue. <Bad idea, adding products like that.  All your doing is causing a constant fluctuation of pH.  VERY stressful on your fish.  Leave the pH alone & keep fish that will thrive in soft water.> Besides rectifying the water quality, how can I get him to eat again?  He still "smells" the food when I try to feed him and he'll also grab a piece or two but then spit it out.  I know he wants to eat but won't.  Also, any suggestions on being able to stabilize my pH and water hardness on a more long term level (as opposed to having to add chemicals every few days)? <All answered above.  Get those nitrates down, try live worms.  I hope you have a HUGE tank, mine grew to 2', before I had to rehome him--tired of replanting my whole tank every morning!  ~PP> Please help, I really don't want to lose this guy. Thanks, Steve

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