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FAQs about "Freshwater" Morays Eels 2  

Related FAQs: FW Morays 1, FW Moray ID, FW Moray Behavior, FW Moray Compatibility, FW Moray Selection, FW Moray Systems, FW Moray Feeding, FW Moray Disease, FW Moray Reproduction, Marine Moray Eels

Related Articles: Freshwater Moray Eels by Marco Lichtenberger, Freshwater Moray Eels by Bob Fenner, Moray Eels, Other Marine Eels, 

Echidna rhodochilus, finally. Feeding       10/28/17
Hello Bob, Neale, Marco and all you good people in WetWebMedia, After years of searching, I finally obtained a small Echidna rhodochilus (35cm), and I'd like to share its pictures with you. It's a lovely eel, but very amusing, just minutes after being released in my aquarium, it already terrorized my shrimps and ate two of them.
The previous owner hand-caught this eel from a river mouth called Muara Tawar in North Bekasi, a neighboring city of Jakarta. He already kept this eel in his aquarium for about a year, in the same water from the river where he caught it, and haven't weaned it off live food yet. This particular Echidna won't eat dead shrimp. Since I have steady access to live shrimps, I don't mind this. But I heard that eels love a variety of different foods, so, If I put Sailfin mollies in the aquarium, will they causes harm to the Echidna if it eats them?
Thank you and have a nice weekend!
Best Regards,
Ben
<Hello Ben. Congratulations on getting hold of this fish! Nope, Poecilia species are harmless, at least in terms of thiaminase. They are, of course, the same risk as any other farmed fish in terms of internal parasites and pathogens. Home-bred specimens should be safer, so if you have the space and inclination, producing your own livebearer or killifish feeders is relatively safe (though Poeciliids seem to be plagued with Camallanus worms that could transfer from mother to offspring, so even here, I'd be careful). Gut-loaded shrimps are a safer and more natural foodstuff for Echidna species that have, on the whole, crushing dentition for invertebrate prey compared to the pointed teeth of the piscivorous morays from other genera. Gut-loading is important though because crustaceans tend to be high in thiaminase, hence shrimp and prawn meat being considered an unsafe staple diet for these (and other) carnivores. I will also remind you that 'freshwater' morays lose their appetite when the salinity is too low, so kicking up the salinity may be helpful. Bob and Marco have written extensively on this/these fish; see here:
http://www.wetwebmedia.com/FWSubWebIndex/fwmorayeels.htm
http://www.wetwebmedia.com/FWSubWebIndex/fwmorayart.htm
Cheers, Neale.>

Re: Echidna rhodochilus, finally      10/28/17
Hello Neal!
<Ben,>
Thank you for the kind words & advice. That was fast!
<Thanks for the kind words.>
Again many thanks. I think I don't have the inclination to breed the mollies myself, so I'll have to stick with fortified shrimps for now.
Anyway, there are still some shrimps left in the eel tank, and seems like they'll all be consumed within a few days, so, after they're all gone, how
many days should I wait until I put on some more live shrimp?
<I would not overfeed; with subadult to adult predatory fish, the aim is to offer food only when they're actively hunting. Personally, I prefer the "little but often" approach with predators, offering them small daily meals
rather than infrequent big meals, simply because it limits the risk of regurgitation or uneaten food being left in the tank. Other people prefer a more 'natural' approach where the fish receives a substantial meal, but maybe 2-3 times a week, but taking care to remove any regurgitated or leftover food before water quality was compromised. But whatever approach you take, a couple notes about Morays. First, they hunt by smell. Adding too many food items at once means the 'smell' gets spread around the tank, and the Moray can have trouble finding it. So get some long forceps or something like a kebob or satay skewer, use this to hold a single food item, and place the item somewhere just upstream of the Moray. Wiggling the food enticingly can help, especially if the food is silvery, like a small piece of fish. If the Moray is settled and hungry, it will start hunting.
The second time is to keep the food bite-sized. Morays can't chew, and despite their ferocious reputation, they actually favour small, easily swallowed food items. Once the food item is taken, repeat a few minutes later. If the Moray shows no interest, it's probably had enough, and you can skip feeding until tomorrow or the next day.>
This particular Echidna Rhodochilus is already 30 cm in length so I assume it is an adult, which shouldn't be overfeed, right?
<Quite so.>
And thank you also for the advice for raising salinity when necessary. I'll try to find a hydrometer so I know exactly what is the salinity rate of my eel tank & adjust accordingly. I have access to seawater (the blessed life of people who lives in coastal cities & not far from estuaries :D ) so it's not inconvenient to mix some seawater to the eel tank.
<Indeed! Sounds nice, especially if you can vary the salinity periodically, up or down, as you see fit. Brackish water fish appreciate this, even though they don't need it. Often you'll see them perk up their behaviour almost as if they're exploring a new tank.>
Best Regards,
Ben
<And to you. Cheers, Neale.>
Re: Echidna rhodochilus, finally      10/28/17

Hello Neale,
Again, many thanks for the feeding info & salinity tips!
<Welcome.>
Speaking of feeding, the remaining shrimps are rather large, and when I turn down the lights, they gather above the Echidna's cave. I wonder what's going on? Are they teasing the eel?
<Nope. More than likely scavenging, and if the Moray withdraws to his cave to eat his food, there could be all sorts of small food fragments thereabouts attracting them.>
As in "hah, we're too big for you, you cant eat us, heh heh!"? Should I evict them later?
<Unless they recognise the Moray as a threat, there's no reason for prey animals to keep away.>
Best Regards,
Ben
<Those are quite big shrimps, for sure! But gut-loading with traditional fish flake, Spirulina and, if you can get it, Sushi Nori algae sheets, will all help to boost their vitamin content and turn them into useful food items. There are marine-grade vitamin supplements, such as Selcon, that can be used -- sparingly -- to good effect as well. With freshwater and marine carnivores, a lot of failure over the long term -- months, years after purchase -- may be explained by lack of vitamins, including Thiamine.
Longer term of course, getting your Moray onto a fresh and frozen diet will be helpful. Cheers, Neale.>

Re: Echidna rhodochilus, finally      10/29/17
Good day Neale!
<Ben,>
Thank you for the tips for fortifying the feeder shrimps. I can give them both fish flakes (available here) and the nori seaweed (I think I saw them on a mall somewhere). The Echidna is so cute, it is worth all the efforts to give it a good home.
<Quite so. A nice fish, and like all Morays, amply rewards good care.>
Speaking of home, I just find this video on YouTube, of a Gymnothorax Tile sharing an aquarium with a Polypterus, both seemed to be at peace with each other, and both still retain their huge appetite for food (though their owner seems to be able to wean the G. Tile away from live food & able to give it frozen shrimp...)
https://www.youtube.com/watch?v=bFXue8NHFRs
Is this some kind of black magic, or is there some kind of chemical stuffs involved?
<No, just luck and time. Gymnothorax tile WILL NOT live its full lifespan in freshwater, and that specimens just a baby.>
G. Tiles are supposed to be brackish water to marine species, while Polypterus are totally freshwater species.
<Yes and yes.>
How could they share the same aquarium like this, without affecting their appetite and behavior?
<The "freshwater" Morays certainly do live some months in freshwater, and youngsters maybe even a year or more. But eventually, without fail, they stop eating. Aquarists who fail to give them brackish water usually end up with a starved, then dead, Moray.>
If this is a brackish water setup, maybe the Polypterus has some tolerance to higher salinity?
<Unlikely. While the Ropefish, Erpetoichthys calabaricus, has some tolerance for slightly brackish conditions, I'm not aware of any true Bichirs in even slightly brackish habitats.>
If yes, maybe I'll introduce a Polypterus or two to keep my Echidna accompanied. What do you think?
<Bad idea. Morays make poor companions. The fact they hunt by smell means they sometimes bite their tankmates! I'd tend to keep yours either singly, or in due course, with some large, robust brackish or marine companions --
big sleeper gobies, brackish water lionfish, toadfish, that sort of thing, maybe even Scats and Monos if you had enough swimming space for them. In low-end marine tanks, pretty much anything will work, including robust
Damsels and Sergeant Majors. Any of these would make more realistic companions.>
Best Regards,
Ben
<Welcome. Neale.>

Re: Echidna rhodochilus, finally     10/30/17
Hello Neale,
<Ben,>
Thank you for confirming my thoughts. Everything I read about G. Tile online pointed out that this particular fish is more brackish to marine than freshwater.
<Quite possibly migratory; Fishbase suggests an anadromous life cycle, living in the sea or estuaries, but spawning in the freshwater parts of rivers. In any event, the experience of those keeping this species suggests brackish will work fine long term, but freshwater doesn't.>
So, I understand that combination of Polypterus and G. Tile is "suicidal", if it's too brackish, the Polypterus would eventually suffer, if it's too fresh, the G. Tile will suffer. Not good!
<Indeed. Suicidal would suggest either of the fish are choosing to die in the wrong conditions -- not the case here!>
As for my Echidna, for now I will let it enjoy the tank by itself and its prey shrimps. This little guy really has personality, I noticed that if the lights are bright, it will behave like a dragon on its lair, sitting nicely on its cave. But when the lights are dimmed, after awhile it will start to "patrol" its surroundings & terrorizing the shrimps. Fascinating isn't it?
<Absolutely, and precisely how they behave in the wild. During the daytime Morays are inactive but not asleep, and will indeed lurk with their heads poking out, showing an interest in what's happening in their part of the world. At night they become active, and that's when they hunt.>
I will eventually get a friend for the Echidna. Sleeper goby sounds cool, and it's a fierce-looking fish, just like the Echidna, so they will make a great conversation piece.
<There are some excellent large Sleepers out there, but do bear in mind such tankmates need to be at least as big as the Moray, otherwise biting is a risk; even if the Moray doesn't actually kill the target, its bites can quickly become infected.>
I am thinking to get myself a G. Polyuranodon, but I wonder, will they get along together?
<Morays can get along in very large systems with plenty of caves, but they can be unpredictable, so I would tend to keep them singly. Do read here: http://www.wetwebmedia.com/fwsubwebindex/fwmorayart.htm
There's a section on tankmates.>
Have a wonderful day!
Ben
<It's almost bedtime here, so will save that for tomorrow! Cheers, Neale.>

Re: Echidna rhodochilus, finally     10/31/17
Hello Neale,
<Ben,>
Thank you for the interesting info about G. Tile behavior. Of all three species that is labeled "Freshwater Moray", perhaps G. Tile is the least deserving of the title. G. Polyuranodon perhaps is the most deserving, but even so, I think G. Polyuranodon and E. Rhodochilus will do better in slightly brackish water, as it's their natural habitat.
<Indeed. But I'm not sure any true eel (Anguilliformes) is 100% freshwater -- even the true freshwater eels, Anguilla spp., return to the sea to breed. My assumption would be that freshwater morays will have a marine
stage to their life cycle, at the very least, and even Gymnothorax polyuranodon is rarely found more than a few km inland, indicating that even though adults do seem to be primarily freshwater to low-end brackish, they do need to be able to get to the sea to breed properly (whether directly or via planktonic larvae I do not know, and don't think anyone else does either). Do see, for example, here:
https://www.ncbi.nlm.nih.gov/pubmed/21722111
Plus the various Fishbase articles on freshwater morays.>
Today I went to the seashore to collect some seawater (about two bottles of 600 milliliters), will mix some of it to my Echidna Rhodochilus aquarium sometime later, to change the salinity, and let's see how the Echidna behaves afterwards.
<Cool.>
I am still unable to find any local fish store which even know what a Hydrometer is, and I am too poor (for now) to buy it online from abroad, but I'll keep searching.
<For brackish, they're not essential. If you mix, say, one bucket of seawater with three buckets of freshwater, you'll have around 25% normal seawater, i.e., SG 1.005 at 25 C. That's fine for most brackish water fish.
Provided each water change is done with something along these lines, one part seawater to three parts freshwater, any slight discrepancy in specific gravity (or salinity) won't be enough to cause harm to your fish or filter.>
Thank you and have a nice day!
Ben
<Welcome! Neale.>

Re: Echidna rhodochilus, finally      11/1/17
Good day Neale,
<Hi Ben!>
Yesterday I have mixed approx 1000 ml of seawater, taken from the beach of Jakarta, to the Echidna aquarium. I also decided to take out the ugly white pipe and replace it with two shorter, darker pipes, which matches my
aquarium better. Echidna seems to like it better, as he seem to enjoy chasing shrimps round and round the two pipes.
<No doubt. PVC pipes are fine, but they do reflect light unnaturally. Can work nicely once covered with a bit of algae though, or if buried in coral rubble.>
After the seawater addition, Echidna still behaves more or less before, except for a few changes. I notice that it is now "calmer", not darting around quickly during its "patrols" as often as before. And it seems to leave its cave more often, in favor of the two new pipes. My friend, the one who own a Polyuranodon that I've been trying to buy for years (unsuccessfully), noted that Polyuranodon also behaves more or less the same, if it has more than one hiding places, it will use all of them, not just stuck to one place. Have you observed this with other morays you have seen/kept?
<Yes; Morays are definitely territorial, but they are also curious, and in their way, intelligent. Anyone who has kept Freshwater Eels (Anguilla spp.) will have noticed the same thing. These are 'cunning' animals that learn their territories well, and expect to have a 'get-away' burrow or two that they can use if chased or otherwise molested.>
Anyway, according to Google, my home in Pulomas Jakarta is only 12 km from the sea. The North Bekasi area where my Echidna were caught, has more or less the same distance from the sea, so maybe our rivers here in Pulomas and North Bekasi are not pure freshwater, but perhaps have some brackish water mixed in.
<Possibly, but it may well be that it's plain vanilla freshwater, and the proximity to the sea is more about reproduction, as we've discussed before.
Or it could be these fish are casually migratory. By that I mean they simply swim up or down river as the mood takes them, perhaps several times a year. Adult Scats, for example, certainly do this, and can be found 50 km
inland, even though they are more common in the sea or estuaries. The truth is that we don't really know very much about how brackish water fish live.
They are not well studied by scientists, and fishkeepers are not as experienced with them as reef fish or rainforest fish. People keeping freshwater Morays are doing groundbreaking stuff here, and it's useful to keep notes and discuss with other fishkeepers.>
I'd love to check their salinity once I get my hands on a proper Hydrometer.
<And I'd love to hear what you learn!>
If it's true, that explains how my friend is able to keep Polyuranodon for years simply by using the water from the river, no marine salt required.
<Quite so.>
Thank you for pointing me to Fishbase and the scientific paper. I also find your interesting comment in this forum:
http://www.fishforums.net/threads/identify-my-brackish-moray-eel.105762/
<Oh! That's going back a while.>
You said: "...Gymnothorax polyuranodon for example is said to be a catadromous species, that is, while adults may inhabit brackish or fresh waters for extended periods, they return to the sea to breed. This agrees with Schafer's records of these fish being found 'a long way upstream in completely fresh water'....Gymnothorax tile on the other hand is *suggested* to be anadromous, meaning that it inhabits brackish and marine waters as an adult but breeds in brackish or fresh water....Echidna rhodochilus isn't referred to as either, so by implication may be euryhaline, swimming and breeding wherever it wants..."
<Hmm...>
I found it so fascinating. So, there are not much scientific infos about Echidna Rhodochilus?
<Not really, no. If you Google 'Echidna rhodochilus' you will get some links, including a first report of the species from mangroves of the
Andaman & Nicobar Islands, which is cool. I do suspect they're simply plain vanilla euryhaline brackish water Morays, rather than true freshwater species, as might be the case for (adult) Gymnothorax polyuranodon.>
That's too bad. I hope my observations here on my own aquarium will help to shed some lights on this fascinating fish.
<As do I.>
I also hope that someday people would find a way to breed Echidna Rhodochilus. I think it's the ideal pet moray. It stays small, not so aggressive, it's freshwater to brackish, it's very cute and it has long live if taken care properly.
<It does seem to be a very good aquarium fish, given the right conditions.
Some of the smaller marine Morays have a well-earned place as rock-solid aquarium residents, and with a bit of care, Echidna rhodochilus would seem to be much the same sort of fish. Healthy specimens are really gorgeous,
with a lovely velvety sheen, and as you say, they're relatively mellow -- though I wouldn't trust them with small or delicate tankmates.>
Well, have a nice day and thank you again for your wonderful discussions, you're very kind & a true expert of this field!
<Thanks for the kind words.>
Best Regards,
Ben
<Cheers, Neale.>


Re: Echidna rhodochilus, finally    11/3/17
Hello Neale,
<Ben,>
Thank you for your advice about the PVC pipe. Tonight I took out Echidna's cave and replaced the PVC pipe back in. I noticed that the cave has rough edges and I am afraid Echidna will scrape and hurt itself on those edges.
<Can certainly be a risk, but these eels do inhabit oyster reefs and mangroves, so probably have some common sense here. Nonetheless, "safety first" is a good maxim!>
Here is a clip of my lovely Echidna before I took out its cave. I hope it will forgive me. My friend told me that Echidna Rhodhocilus are not as easily stressed as other morays, is that true?
<Probably; they are physiologically adaptable, that is sure. Morays are hardy anyway, and among the tougher marine fish, so a euryhaline one is likely to be remarkably durable. The flip side though is that they've been
abused a bit over the years, kept in freshwater systems for too long, and surely some have died prematurely because of that. We don't really know that much about their diet and reproduction either, so might be missing
important things in those directions.>
https://www.youtube.com/watch?v=McgRWm92xN8
<Nice!>
I am fascinated with your info that it is us, Freshwater Moray keepers, who are leading the (informal) research on FW moray behavior. I want to share this video clip with you, sent to me by my friend who keep several Polyuranodons.... in "FRESHWATER" for years ("Freshwater" because I he said he just fill his aquarium with the water from the river where he caught the eels, but I never ran a salinity check on those waters).....and after
years, he was able to train his Polyuranodons to eat BLOODWORMS... Isn't it amazing? Here is the clip:
https://www.youtube.com/watch?v=816Z5mD9NDs
<Likely a major source of nutrition in the wild. Mosquito larvae are very common -- and very important -- parts of the freshwater food chain. They are also common in brackish water habitats too.>
Now you can put it on your notes, that there is a prove case from Indonesia, of Polyuranodons actually kept in "freshwater" for years and trained to eat bloodworms!
<Your messages are shared with everyone who reads WWM, whether now or in the future!>
Off course, we have to take into account that this is Indonesia, the natural habitat of these eels, and they are being kept in the water from their own rivers, and the surrounding temperature is pretty much the same
(they are literally being kept in a city of the same island where they were taken from). Therefore this should not be interpreted that I am advising fish lovers in other countries (especially Western!) to start keeping Polyuranodon on freshwater and feed them bloodworms, I don't! Because what works here in Indonesia might not work in other places.
<Quite so. Your specimens have endured less handling and shipping -- it can easily be months between capture and ending up in an American or European aquarist's fish tank. That will make a difference.>
Well, thank you for your continuing attention and support!
Best Regards,
Ben
<Always glad to talk. Cheers, Neale.>

Re: Echidna rhodochilus, finally      11/6/17
Hello Neale,
Again, many thanks for your input & continuing support! WetWebMedia is really blessing for all of us fish-lovers everywhere!
<Thanks for the kind words.>
Now I am inspired to train my Echidna to eat bloodworm too. Will post here the results, though I am sure it will take a while. Maybe I will get another Echidna as well, because what's better than one Echidna Rhodochilus? TWO Echidna Rhodochilus! :D
<If they get along, at least...>
I will also try to acquire a G. Polyuranodon for the same purpose. Maybe when I get two Echidnas, I will trade one for a G. Polyuranodon :D
I have thoughts on obtaining a G. Tile, however this species grows big, and I don't have that much space in my current house for another aquarium.
Plus, though it is a known species in this part of Indonesia where I live, G. tile and E. Rhodochilus are harder to find than G. Polyuranodon or even E. Nebulosa.
<Really?>
Getting an FW moray around here is a bit tricky, because these days most of our local fish catchers who supply ornamental fishes for fish shops, does not really understand the taxonomy of the fishes. They use "catch-all"
terms for the fishes, for example, any eel types they caught in the estuarium, they will say "It's a Belut Muara" (estuarian eel), whether it's Gymnothorax Tile or Gymnothorax Undulatus or Echidna Nebulosa or even Gymnothorax javanicus. I have to inspect what they caught, and sort the fishes by myself.
<Interestingly, when I Google the "Belut Muara" name I end up with mostly Synbranchus-type swamp eels, such as Macrotrema caligans. These are brackish-tolerant freshwater fish, more of low-end systems than mid-to-high
salinity systems. Synbranchus eels tend to be extremely aggressive and predatory, so approach with care.>
It's much more effective to buy the fishes from hobbyists who hand-caught their stocks, and know enough taxonomy to identify what they have caught... but then, these hobbyists often developed emotional attachments to their pets & won't sell their favorite ones.
<Indeed.>
Well, this has been a wonderful discussion, I hope it will be useful for WetWebMedia readers & all "FW" moray lovers everywhere.
Thank you & Best Regards,
Ben
<And you; cheers! Neale.>

Re: Echidna rhodochilus, finally     11/15/17
Hello Neale and all you good people in WetWebMedia,
<Hello Ben,>
As I promised, here is the latest update of my Echidna Rhodochilus.
1. After I raised the salinity by pouring in seawater gradually, I noticed that sand sticks on echidna's slime coat. I thought it was some kind of disease, but when i gently touched the echidna, the sand came off. So I stopped raising the salinity, at the weekly water change I no longer add seawater & did the water change using freshwater from my well. Just a few days after, echidna went back to normal with no more sticking sands.
<Quite normal behaviour. Mucous production is one way that scale-less fishes like eels adapt to their environment. It's perfectly normal for them to produce extra mucous at times, and eels of all kinds are famous for
doing this. It may well be that salinity changes trigger mucous production, perhaps because it slows down water loss in more saline water.>
2. Echidna Rhodochilus are amongst the smallest of the moray, but they are actually strong enough to rearrange their aquarium. My echidna is able to uproot my bogwood ornament and moving its home pipes around as it sees fit. It is more active now than weeks ago when I first got it.
<Again, eels are noted for their strength. Despite their sluggish behaviour during the day time, they are actually effective and powerful predators at night.>
3. It is very docile though, it never made any attempt to bite me whenever I stick my hands inside the aquarium to put the pipes and bogwood back in place.
<On the whole Morays are known to be curious rather than aggressive towards people, even wild Morays in the oceans.>
4. Maybe later, I'll temporarily (not long-term, maybe just days) put docile pet fish from my other aquarium to test their compatibility with Echidna in a semi/low-end brackish condition. I have a Monopterus albus which are larger than the Echidna, and whose docility are guaranteed, it has been housed for years with two Polypterus palmas, three clown loaches and two yo-yo loaches, and it never caused trouble. Seems like a perfect candidate for the experiment. Or maybe I put the clown loaches, as they have grown rather big and I am sure echidna won't see them as food.
<Does sound like a good candidate for this, but I will caution you that Synbranchids are often reported to bite companion fish, so keep a close eye on things.>
And thank you for the tips in selecting caught fish. We never know what got caught by local fish catcher here. Besides aggressive eels. sometimes even marine food-fish like ikan layur/ribbon fish (Trichiurus lepturus) end up
in estuarium and get caught. Those fishes has nasty teeth!
<What a cool beast! One of the neatest fish I've seen in aquarium shops in England is another eel, Congresox talabonoides, sometimes called the Pike Conger Eel. It's a brackish to marine fish, and seems quite hardy and
peaceful. But it is predatory, and apparently sometimes reaches over 200 cm in length!>
Best Regards,
Ben
<Thanks for the photos. Cheers, Neale.>


small error       9/5/17
60 cm is 24 INCHES, not 24 FEET.

<Hee!>
Species
The by far most common moray eel sold as a freshwater fish is Gymnothorax tile, it is often simply referred to as 'freshwater moray eel'. Sometimes it is labeled 'Indian mud moray', 'snowflake eel' (not to be confused with the other 'snowflake eel' Echidna nebulosa) or 'gold dust moray'. It is grey and has numerous yellow to golden spots spread on the dorsal and lateral part of the body. With age the yellow spots become smaller giving the adults a more or less uniform grey appearance. They are common in the Sundaban mangrove swamps in East India, but they are also distributed in Indonesia, the Philippines and the Andaman Islands. The species reaches a maximum length of 60 cm (24').
<Can you tell me the URL where you found this error? Thank you, Bob Fenner>
Ahh, I found it: http://www.wetwebmedia.com/fwsubwebindex/fwmorayart.htm
Thanks again. BobF

Re: bumblebee grouper in freshwater? Plus now, FW Moray      6/24/17
Hello Neale!
Thank you for the detailed and fascinating reply.
<You're welcome.>
I understand your explanation. We Indonesians are blessed to live in the tropics; and many of our native fishes which are "common animal" for us, are often "luxury pets" for people in another part of the world.
<Precisely.>
People in Europe and USA would have to be more careful in choosing the best tropical fishes for their system, and ensuring that they buy only the animals which are compatible with the aquariums they have. Otherwise, it's
money wasted, and precious live fish wasted :(
<Quite so. If you're experimenting with a common brackish water fish, one that would just as likely end up on a dinner plate, then seeing how it would do in a freshwater tank is understandable. Of course nobody wants to
kill a fish slowly across weeks or months, so if the fish stops eating or starts getting sickly, then switch it back to brackish water conditions.
But if it's fine, then I don't see the harm.>
And certainly any fish that could grow bigger than one meter, like those poor groupers, are not ideal pets :( better let them swim free in the ocean..
<In this case, yes, probably best.>
It is fascinating to read that individual variations does matter in the survival of brackish/marine species in freshwater.
<Among all species, actually. Just think about humans -- all one species, but with very slight variations that make individuals better at handling different levels of UV exposure, oxygen availability, ability to digest milk as adults, ability to resist diseases like cystic fibrosis and malaria -- all sorts of minor genetic changes that evolution can work with. Nothing big enough to stop us all being humans, but things that mean a person well suited to one part of the world would be less well suited to another. This is the golden rule of biology -- the more variation, the better it is for the species. Doesn't matter if you're a human or a fish!>
As a matter of fact, I know a fish enthusiast who kept Gymnothorax Polyuranodon in freshwater for many years, with no apparent bad effects to the eel (I tried to buy it from him many times, never succeeded). He did not buy the eel from a fish shop, he bought it directly from a fisherman who fished the eel out of a river in Cilacap, South Java.
<There may well be regional populations of this Moray better adapted to living in freshwater. But if the ones traded internationally are from estuaries near the big cities, then those are the ones aquarists in Europe and the US will have to deal with. This is known for some Archerfish species, including species ordinarily thought of as brackish water fish known to breed at sea, but in some cases with landlocked populations that clearly don't do this. Because those landlocked populations are never traded, the standard advice to keep Toxotes jaculatrix and T. chatareus in brackish water aquaria is good advice -- unless of course you happen to live local to a true freshwater population and can collect them yourself!>
Perhaps this is a case of a lucky eel, because I read in the web, sad stories of morays who became stressed (some even died) after being kept in freshwater.
<Indeed; they commonly stop feeding, and after a few weeks or months, just die.>
I attach the picture of his eel with this picture.
<Do I see an Anabas climbing perch in there? Neat fish; never had the chance to keep one, but on my wish list!>
He mentioned that he does not use any chemical formula, not even marine salt, he just put the eel in the aquarium (together with some Anguilla bicolors), and use the water taken from a nearby river, mixed with tap water.
<Not so easy if you live in England!>
Well, again thank you for the discussion, and I wish you a wonderful weekend!
Best Regards,
Ben
<Thanks for writing and sharing these photos. Cheers, Neale.>

Gold dust eel... Non-FW moray        4/11/17
Hi there,
<Winnie>
I am very lost. My first time to have a gold dust eel. I'm not sure what's happening to it. Pls help me.. what should I do..
<? Need data... is this fish being kept in brackish conditions? Water quality test results? READ here:
http://www.wetwebmedia.com/fwsubwebindex/fwmorayart.htm
and the linked files above (FAQs); re systems, feeding... Disease. Bob Fenner>

Gold dust eel /Neale        4/12/17
Hi there,
I am very lost. My first time to have a gold dust eel. I'm not sure what's happening to it. Pls help me.. what should I do..
<Hello Winnie. Judging by the Stingray, your Gold Dust Eel is in a freshwater aquarium. He WILL NOT LIVE in a freshwater aquarium. These are brackish to marine species. Given your obvious expertise if you're keeping
Stingrays, let me immediately direct you to some reading:
http://www.wetwebmedia.com/fwsubwebindex/fwmorayart.htm
I'd also be dosing with an antibiotic, but once in brackish or marine conditions, your Moray has a good chance of recovery. Unfortunately, in freshwater tanks they INVARIABLY stop feeding eventually, and over time, lose their vitality and energy, eventually dying from a bacterial infection, osmotic stress, starvation, or some combination of these. The precise salinity doesn't matter too much, but 25-50% normal marine is about right, i.e., about SG 1.005 to 1.010. Cheers, Neale.>

Some help... FW/BR Eel/s bet      8/26/15
Hello,hi my name is Terry and I have a friend whom works at petco,and first let me say I really don't like petco nor how they don't teach there people right...I am a animal lover and I know alil about a lot and animals are my thing and I know there isn't a true 100% freshwater Eel and that petco sells a Eel (snowflake Eel) itz a snowflake 100% Eel not that all white one,with black flakes and yellow tint but tha other somw white with like black spots and they are sellin these animals a frehwater Eels...well I tryed 2 educate my friend whom says he has been doin this for 12years that there is no true 100% Eel that is freshwater and that snowflake Eel isn't either 1 freshwater...well u said that I am wrong and that he don't know where I get my info but I am wrong,I said with a lol that he is wrong and I said I woulda bet him 100.00s with a slight pause he lol and said no but he said if I showed him a book backed with science pro that ima right and he's wrong (book) that he'll pay me back and buy my snowflake Eel I said oka ur on...
<Indeed.>
Now I do all my readin and kept readin and stay readin and know my stuff...what I need from u guys even tho it states right here that he is wrong on ur page can u give me a name of a book or somethin else so he can c it and read it 100% and that I am right,
<Well, you could start with the book I (Neale Monks) edited, 'Brackish Water Fishes' published by TFH. Or you can try the Aqualog book 'Brackish Water Fishes' by Frank Schaefer. Both discuss the several "freshwater"
morays in depth. You can also visit the relevant page on my Brackish FAQ to find links to the Fishbase pages for each of the three traded species, here:
http://brackishfaq.webspace.virginmedia.com/Projects/FAQ/4f.html
While all three species occur in freshwater at certain times in their life, none spend their entire life in freshwater, and all become sickly if kept in freshwater tanks indefinitely. Indeed, it's probable that the three of them migrate into and breed in the sea only (that's what all other eels do).>
not just 4 my benifit but tha well bein of those animals and that he can listen and learn somethin 2 pass it on...plus I've been wantin a snowflake Eel and set up a 65gallon tank,with live rock,dryed live rock,coralife super skimmer 65g,I plan on up gradin my skimmer and at somme point make,build a 40g wide tank I want 2 start coral and frags...
I want 2 get deeper in2 tha saltwater trade just 2 have a small piece of heaven sea world right here at home and give them a beautiful home.
Thank u sincerly Terry...
<Hope that this helps. Cheers, Neale>
re: Some help... BR eels not FW        8/29/15

Thank u for all...
It don't matter to my friend I guess, he keeps telling me he'll take me to our public library and show me that ima wrong...lol
<Indeed, LOL.>
I told him about u Neale monks and ur back ground I looked u up and wrote everything down 4 him, and gave him his scientific evidence that he was wrong and u held all tha truth...it did no good he still say I am wrong that u are wrong..lol that's funny, I don't believe he even read anything...
<A common problem.>
I told him ill even show him are emails, hard headed I guess...I don't understand why he believes in a library book that some other dude wrote but willnt believe urs...
<Some folks don't want to have their minds changed. Even when deep down they know something is wrong. They still hold onto what they think and feel because it's easier than to change their mind and admit they were wrong.
Sometimes people just have to learn things the hard way, in this case, with sick/dead fish. Shame on them, but at the end of the day, "you can take a mule to a well but you can't make it drink".>
I don't know what 2 do he with my friend...
<Have your friend email us if wants, and I'd be happy to chat. Meantime, encourage him to strive to become a Master Fishkeeper, someone who reads up on the science and visits the library alongside wanting to develop the practical skills. We can all be better fishkeepers! Cheers, Neale.>
re: Some help... (Bob, Snowflake Eel???)        9/2/15

Mr. neale,I am stoked, I got my baby snowflake Eel today, she I call her is about 7inch beautiful color and I also found out how to tell what type of snowflake Eel one has by color ...but at any rate, I have a issue my Eel was shipped over night to me from thatpetplace.com and when I opened it up and seen her I loved her from that moment, I have a issue though she seems to be twitching a little bit head shakes and I wanted to know is that normal and is there a issue I need to worry about???
<Not normal, no, so would investigate. Check water quality, chemistry and salinity. Morays are quite hardy but they do get stressed by handling. Would have you read here:
http://www.wetwebmedia.com/snowflakemoray.htm
Do follow the links at top... especially the ones on disease, behaviour and systems. Unhappy Morays will try to jump out, and they're also among the first fish to suffer from external parasites, so there are some immediate risks/considerations. Good luck with this lovely fish. Cheers, Neale.>

Hello
I recently bought a marble moray eel ("freshwater)      1/30/14
<Uhh, BR>
who seemed to be doing great until I found it dead today after work.
<Quite common; most specimens are "lost mysteriously". Not an "aquarium hardy" species>
All water conditions are perfect, the tank has been up for a little under a year, and I have a great deal of salt in the water since they are brackish creatures. She didn't stop eating, she wasn't having labored "breathing", and her color was beautiful. I found her belly up on the floor, and her stomach seemed to have been opened with lots of attached little beads hanging out. Any idea of what could have happened?
<Read here: http://www.wetwebmedia.com/FWSubWebIndex/fwmoraydisfaqs.htm
and the linked files above. Bob Fenner> 

Gymnothorax Tile: Slime coat and compatibility concern    12/25/12
Hello. About 3-4 weeks ago after much consideration I purchased a Gymnothorax tile from the fish store I work at. We kept them at about 1.010-1.013 salinity, and had them for several months before I decided to bring mine home.
He is currently in a 29 gallon tank, that will be upgraded within 2 months to at least a 50 breeder. He is roughly 8". Tank was running as a freshwater tank for one year, and I converted it to brackish using marine salt. Salinity is 1.014. Ph: 7.8, Ammonia: 0, Nitrite: 0, Nitrate: 20. Temp is 78 degrees Fahrenheit, and is currently running on an Eheim ECCO and a sponge filter. I do 20-25% water changes twice a week. Considering running a Hydor circulation pump at the surface, but not sure if it will be too much water flow.
<I've kept and keep various moray eel species (including G. tile) in tanks with turnover rates of more than 30 times per hour. I don't think the eels care at all. A strong surface current does increase gaseous exchange, which will benefit the system in general. The fine sand, however, might develop ripples.>
Fine sandy bottom with plenty of PVC caves, thinking of adding lace rock and creating more natural caves. He has one tank mate, a Batrachomoeus trispinosus, another so-called 'freshwater' fish.
<A very interesting species.>
These two were in the store tank together for approximately 4 months. The eel gets fed 3 times a week. I have been feeding him krill, clam strips, and lance fish so far. Thinking of adding ghost shrimp harvested from my freshwater tanks and earthworms to his diet.
<Sounds good to me. I'd mostly replace krill with some other, larger crustaceans in the future and add vitamins about once a week if mostly frozen food is fed.>
He seems good appetite and activity wise (active at appropriate times), but when he comes out to feed I've noticed what appears to be sand sticking to the slime coat of his belly. If I stick my hand in the tank and lightly touch him, it comes right off, but I'm curious if he could be stressed and producing extra slime coat?
<I don't think so. I suppose this is due to an interaction of the specific sand with slime. I have seen this happen mostly with relatively new sand.
Maybe the sand has not developed proper biofilms since you brought the salinity up.>
I didn't notice this in the store, but the sand I chose is very fine and soft, and the sand we had in the store was, I believe, a denser sand marketed for African Cichlids. Otherwise, his color is an even dark grey, with some minor speckling if you look closely farther down his body. No white or faded patches. Any idea what could be causing this? Is there even reason for concern?
<I don't think so and believe this will cease with time.>
Also, is the Batrachomoeus trispinosus compatible long term? or even short term for that matter? If yes, will he handle a full marine conversion the eel requires in the future?
<Please note that Batrachomoeus trispinosus sometimes seems to be confused with Potabatrachus trispinosus due to the same species name, a similar genus name and a somewhat similar overall appearance. Potabatrachus trispinosus is a tiny freshwater fish (2-3") while Batrachomoeus trispinosus gets a foot long and can be caught offshore and in reefs. It's basically a marine fish which also inhabits higher salinity parts of river deltas. They can eat enormous prey items. I believe it will depend on the size of the two fishes, their growth if long term success is possible.>
Thank you for your time, Catherine
<Welcome. Marco.> 

Gymnothorax tile help     4/5/12
Hello, I have bought a Gymnothorax tile about 2 weeks ago from a private listing. After getting to their house to pick up my new pet, I realized that he/she was living in horrible conditions. It was in a 10 gallon tank half full, with no salt, poor filtration, and horrible water conditions. After getting him/her home, I did a major tank clean (I know not the best idea, but his/her water was really that bad I had no other option), added water conditioner and let him be for a couple days. I then slowly started adding Instant Ocean marine salt, I do not know the exact measurements, I will be getting a hydrometer tomorrow,
<Yes, you'll need that.>
but I have added about 1 cup less than a half of a box (I was told that I should do half the recommended dose) that was specifically measured for a 10 gallon tank, which is what he is still currently in.
<Much too small. You should also get a larger tank in the near future.>
I have upgraded his filtration system to 2 filters made for 10-30 gallons, and added a heater. Right now his tank is about 28 degrees Celsius.
<24-26°C is enough. The water will carry more oxygen at lower temperatures, which should help a little in this small, uncycled system.>
He is currently on a steady diet of shrimp, they were feeding him cubed ham which after doing research I found was a big no-no, I will be introducing silversides into his diet tomorrow.
<Silversides can be fed regularly, but should not be the main part of the diet. It's important to get the diet mixed a lot. See http://www.wetwebmedia.com/ca/volume_4/V4I2/Freshwater_eels/freshwater_eels.htm >
Ok with all that being said, my Gymnothorax tile has been acting very strange lately. He seems to be struggling to breathe on and off throughout the day,  flipping upside down and laying there for a few seconds, and then violently thrashing his tail back and forth creating craters in his sandy bottom. I am new to owning this species, and have done all the research that I can, but I just can't figure out if his behavior is normal.
<Likely an environmental problem due to the small and probably still uncycled system.>
Will he/she be ok, and is there something that I am doing wrong? Please help.
<The best for its survival would be to get it into a larger, well established marine system until you can provide a sufficient one. If you instead of that wish to use your current tank, get a test kit for ammonia and one for nitrates in addition to a hydrometer and more salt. The test kits will show when you should change water (basically you are cycling the tank with a fish in it now due to the major tank clean). Any ammonia measurement >0 or nitrates above 20-25 ppm are a reason for a water change. Also, keep the water surface moved with what filters you have available. When you reach marine salinity (check with the hydrometer) you can add well cured live rock to help with the filtration. In the mean time you should get a larger tank and start cycling it without fish. Later you can transfer your moray and the live rock to the larger tank and get rid of the small one or use it for something else.>
Thank you for your time, Stephanie
<Good luck. Marco.>
Re "Freshwater" Moray Eel Two Questions, fdg., sys.    4/9/12

Hi again, this is Alyson (the one with the "piggy" Gymnothorax tile) Since we last spoke I have been feeding him lesser and lesser each day to get him used to eating every other day. He is doing fine, keeps "begging" but I just don't look at him lol.
<Sounds good.>
I did have just two more additional questions....I was planning on purchasing another Gymnothorax tile and I have read on your site that they can live together and normally don't show any type of aggression towards one another.
<Yes, this works best if both (or more) are introduced to the tank
together, but adding another one generally works, too, with this species.>
I was just wondering if I do actually purchase an additional eel should I look for any "hints" that two are being aggressive towards one another <There may be an initial 'fight' at first contact, since one has established its territory, but if there are enough caves it should be no problem.
Rearranging some rocks/caves (without turning the tank into a cloudy mess of course) before adding the new one can also help.>
and also my specific gravity is already at 1.020-1.021....would this hurt the "new eel" moving him into that high of a level so soon after purchasing him?? (that's assuming the idiotic pet store has him in full freshwater, which they normally do)
<Acclimation can be rather quick. If you want to be on the safe side try this: Put the new eel with the water it was transported in into a bucket (add a small airstone if you have one at hand) with lid. Add tank water over about one or two hours until about 70-90% of the water in the bucket is tank water. You can use a cup or an air hose with a loose knot. Then, add the eel to the display or if available quarantine tank. The acclimation procedure can be combined with a small water change, since you have to replace the tank water you added to the bucket if you wish to avoid adding water from the store to your tank.>
I appreciate all of your help and hope to hear from you soon! Thanks
<Welcome. Marco.>
Re: Another issue Marco :(, G. tile      4/29/12

Hi again Marco, it's once again Alyson.
<Hello there.>
I feel so bad for pestering you with my questions/concerns :(  I live in North Carolina, USA (do not know where you are located),
<Southern Germany, near Heidelberg.>
but I can not find vitamin supplements anywhere for my eel's food. There are 6 pet stores and no one has them and don't even know what I'm talking about (Haha I know right), so my question to you is there a brand/site that you can recommend so that I can order it over the internet for my eel?
<Vita-Chem Marine is not bad. A few drops on the food once or twice per week.>
Also, the only pet store in my city that has live rock is a very "dirty, sick animal type place" so if you can also recommend a good, trustworthy site to order live rock from? If so, that would be awesome.
<I don't have personal experience with online US live rock sellers, I prefer to see the rocks in the store. But I will leave the email in the inbox if someone else has a good online source.>
I know in previous emails you have advised me to get a skimmer, trust me I am definitely saving up for one lol.
<Very good, this will help with waste removal and oxygen supply. Also keep the water surface moved to help with the gaseous exchange.>
I still only have the one Gymnothorax tile, but I ordered another one and it should be in Tuesday so wish me luck.
<Okay.>
Once again, thank you so much for all of your advice and help, although my eel is still laying his head sideways I am going to take your advice and not worry about.
<I guess as long as the water is ok, that's just some stress from the move.>
Thank again and cheers to you too! :)
<Welcome. Marco.>
Hi Marco, another question    5/1/12

Hey again, hopefully this should be my last question for awhile ( I know you're probably thinking thank goodness lol). Since I cannot locally get the vitamin supplements for my eel's food, I was looking at your site and saw some things about being able to add baby and/or human vitamins to fish food.
<Yes, this can be done, although personally I rather use products developed for aquarium use.>
I spent all of today searching the site to see exactly (if so) what types of things to look for if I choose to go that route. I definitely need to add vitamins to Eely's food because although it's a variety, it is mostly frozen. If it is ok and safe to add baby and/or human vitamins, what should I look for and avoid when purchasing?
<Prefer sugar free liquid products high in thiamin.>
Also, how do I go about adding it to an individual feeding?
<Add a few drops after the thawing process and before feeding. If you feed larger foods (little fishes such as silver sides or clams, mussels, shrimps) you can also use a syringe to inject the vitamins into the food.>
And by the way, my new Gymnothorax tile should be in tomorrow (yay).
<Seems it's time to feed the old resident and rearrange some caves to avoid most territorial behaviour.>
Anything you know on supplementing human vitamins for "fish" vitamins would be awesome, if not I will have to order some online. Thanks again.
<Hope this helps. Marco.>
Re: Hi Marco, another question, BR  5/2/12

Hi again Marco, yeah I think I am just going to play it safe and order some vita-chem. marine over the internet. As far as preparing for the new eel
(still waiting for the pet store to call to say it came in) Yesterday I bought some more "caves" and what not and rearranged the tank decor so I am hoping that will help with the "new arrival"  Thanks again for all of your help!
<You're welcome and I hope everything went well. Marco.>
New issue with eel laying with head sideways
Sigh....I thought for sure the last email I sent you would be the last lol.
<Oh... well.>
In previous emails I mentioned that my eel was laying his head sideways out of his cave. Well today he was very active, swimming around, exploring the new tank decor. That is when I noticed between his right eye and nostril, also his lower jaw, was very pale. The patches were not white nor did they look like a "fungus" of any kind. The patches are not on the other side of his face, but the reason that I am concerned is that when he did finally go back into his cave, he was rubbing against it on that same side.
<I guess this may occur due to the movement, stress, new and after only 5 days of cycling quite fresh tank... a skin irritation. Better check your water parameters.>
I was searching your site and saw something about "white spot disease," but the pictures I saw didn't look like what is happening in my case. To be safe, should I treat for Ich??
<No. Not until you know it is Ich (Cryptocaryon irritans). You would notice heavy breathing and white, salt grain like spots. Healthy eels practically never get it due to their toxic slime coat.>
Other than his "scratching" he seems perfectly fine, happy with his new decor and such on, but once again any advice would be helpful. Thanks again!
<Check your water, ensure there is enough oxygen in the tank. Good luck.
Marco.>

Re: once again, another problem :( - 5/12/2012
Hi again Marco, I guess I had forgotten to mention that before placing the "sick eel" in my community tank, I did put it in a quarantine tank 1.To get it used to some salinity and 2. To watch how it was....It seemed relatively fine in the quarantine tank. In regards to the "swollen throat" I either jumped to conclusions thinking it was bacterial or was right. It was also very skinny (I know it had probably not eaten in a while since he was in captivity maybe making his throat seem slightly bigger?). After watching him in the quarantine tank (not showing any signs of sickness) that’s when I decided to move him to the community tank.
wwm: Quarantine is rather a matter of weeks instead of days (or hours).
At first he was swimming around exploring for about 5-6 min and then he just nose dived into the sand and laid side ways. He appeared to have stopped breathing, that’s when my eel went up and nudged him. So, I immediately removed him and put him into the hospital tank and treated him with (you're right I misspelled) Maracyn. I believe it was just too late. He started getting paler and paler and eventually died. Maybe it was bacterial or maybe it was that in combination with stress and starvation I don't know and I'm sure him being kept in freshwater for a long time at the LFS didn't help either. But in response to "putting a sick eel into my tank" I believe I took every precaution before adding him. I quarantined him first and he didn’t not show any signs of "sickness".
wwm: You had the suspicion and I think you were right for quarantining the eel. Won't argue here, though, since this case is closed, all that can be stated is: If you think a fish might be sick don't buy it and if you still do buy it quarantine for some weeks it until you are sure it is healthy.
I was a veterinary technician for many years (we didn’t deal with fish though lol) so I take great care of all of my animals.
wwm: See above for proper times for quarantine. Here's also a good description of a quarantine protocol: http://www.wetwebmedia.com/QuarMarFishes.htm
My eels are like my children and I would never do anything to intentionally hurt them. They are in my home office, so I watch them all day, constantly checking PH, ammonia etc. I just want to make sure I am doing everything I possibly can to ensure they are healthy and have a healthy environment (I guess that’s why I bother you so much with my concerns). As far as my baby eel goes, he has learned not to go into a cave that Eely is in lol and I actually got him to eat 2hrs after purchasing him. Another question is since he is a baby should I keep the water brackish until he grows and then turn to full marine?
wwm: Can perfectly live in marine water even at small sizes.
I read that the juveniles live in brackish and as adults they migrate to full marine so if I could get your advice on that.
wwm: A theory that to my knowledge never was substantiated by usable evidence.
I am still saving for a skimmer (boy, they aren't cheap), but not knowing much about skimmers, can you use them in brackish or just strictly full salt?
wwm: Most start working quite well at brackish salinities, but at higher salinity the surface tension of the water will be higher, so it become easier for stable bubbles and foam to form and more organic material will be removed.
Thanks again. Best wishes, Alyson
Once again, another problem :( - 5/11/2012
Hi Marco,
wwm: Hi Alyson.
I dont know if you remember when I said I ordered a new Gymnothorax tile to add to my tank. Well, it took until yesterday to show up. My local pet store had three, one that was the same size as my G. tile and two babies....Well as I was looking at the "bigger one" I wasnt happy about his throat. It seemed swollen (which led me to believe maybe bacterial infection) and he was not hiding like most eels do. Well, against my doubts I purchased the larger one so that there wouldn't be a "size to size" issue.
wwm: The best option would have been to purchase none of them, but the sick fish is mostly the worst choice.
Needless to say, the eel lasted about 30 min. It was very sad to watch, even my eel was nudging it trying to "wake it up". He was still breathing very shallow, so I immediately moved him to my hospital tank and tried to treat him with Macryn
wwm: Don't know this one. You probably mean Maracyn.
, but I believe it was too late. So (I know exactly what you are going to say lol)
wwm: Like, why did you buy a sick eel and put it in the display tank possibly introducing pathogens instead of the hospital until it heals or dies.
I purchase one of the baby G. tile. Yes I am aware at the bullying that could happen between my larger one and the new one. So far so good. There was an initial fight when the baby tried to go in "Eely's" home and I broke it up. There was no signs of damage to the new eel and in response to that, the baby later on, went up and nipped the bigger eel's tail lol (once again no injuries).
wwm: Doesn't sound too bad so far. Keep an eye on them.
My problem is that after removing the "original new eel who died" my nitrates skyrocketed. I did a 50% water change, but still no change. PH is at 8.0 and ammonia is at 0...Any ideas???
wwm: I don't think this is directly connected to the new eel. The short term solution for high nitrates is water changes, the long term solution is to improve filtration. When you reach marine salinity, a skimmer would likely be a good investion. Until then I think water changes are your best option. Also read here http://www.wetwebmedia.com/nitratesmar.htm and in the linked FAQs.
Once again thanks a lot. Best wishes, Alyson
wwm: Good luck. Marco.

Re: think i fixed nitrate prob. but still more questions     5/18/12
Thanks again Marco, I will monitor these "spots" on the baby eel and if anything changes in regards to that I will definitely contact you (with pics).
<Ok.>
Hope you have a good one.
<Will try.>
As always best wishes, Alyson
<Okay. Marco.>

finally got pics    5/19/12
Hey Marco, I was finally able to pics.....they're not the best in the world, but I tried. It seems to have spread. I know they are a little dark, but it was the best I can do. If you can tell what these patches may be, please let me know as soon as you can.
<Can't tell for sure from the pictures. Does almost look like healing scratches from bite marks or sharp decorations, which would not need treatment. I think with the fish in front of you you'll see if these are possible scratches.>
He is still acting normal, but now since it seems to be spreading, I am thinking it is more likely a disease. Please let me know your thoughts on this.
<If this truly keeps spreading (and only then) I'd get the hospital tank up running and treat with Maracyn (preferably Maracyn 2, since at higher salinities many bacteria seem to be gram negative) suspecting a bacterial infection of the skin.>
I have looked on the WetWebMedia site looking at diseases (especially on eels), but I can't pinpoint what this is according to the pic on your site. I will be waiting for any advice you may have. Thanks again.
<Also, keep the water quality high (tank looks still quite "fresh"), have the surface of the water well moved and feed vitamin enriched food. Good luck. Marco.>

Re: finally got pics... G. tile, ongoing chatting     5/20/12
Thanks for getting back to me Marco. I know those weren't the best pictures in the world, but I don't know if you could tell by them, that the spots didn't look granular like Ich, nor was is filmy like a fungus.
<Both would look completely different.>
The spots are just the same color the eel's belly is. So I'm with you thinking the spots maybe scar tissue. Got a couple more questions though, the same eel (the baby) loves to hang on the filter and on the tops of the plants that I have in there. He acts normal and usually does that after my big eel chases him. He just hangs there and watches curiously as opposed to watching from a cave. I'm assuming he does that to be on the safe side so he doesn't run into the big eel. Would that make sense?
<Yes, I think you need more caves. Create narrow caves like properly sized aquarium hoses covered with rocks, lots of rocks (prefer calcareous material like limestone, dead reef rock). If caves are the better option they will be used. If a cave has a much larger diameter than the eel like many aquarium decoration products, it will not be considered as a top notch living quarter.>
Also I purchased a baby vitamin supplement to add to the food and was wondering if I provided you with the information if you could say if it was safe to use or not?  The product is Enfamil Poly-Vi-Sol
Vitamin A 1500 IU
Vitamin C 35 mg
Vitamin D 400 IU
Vitamin E 5 IU
Thiamin (B1) 0.5 mg
Riboflavin (B2) 0.6 mg
Niacin (B3) 8 mg
Vitamin B6 0.4 mg
Vitamin B12 2mcg
*Ingredients* Glycerin, Water, Ascorbic Acid, Polysorbate 80, Vitamin E Succinate, Niacinamide, Ferrous Sulfate(as a stabilizer for Vitamin B12) Natural and Artificial Flavor, Artificial Caramel Color, Vitamin A Palmitate, Thiamin Hydrochloride, Riboflavin-5-Phosphate Sodium, Vitamin B 6 Hydrochloride, Vitamin D3 Vitamin B12
<Not as ideal as a specific product for fishes, but according to its composition I think it should do its job.>
This product says it is sugar free,
<Glycerin is a polyol compound.>
but I will wait to hear if this would be a good supplement to use or not.
<I think a few drops can be added to the food after thawing and should improve the vitamin supply and not cause problems.>
Thanks again for your time!
<Welcome. Marco.>
Re: finally got pics      6/3/12

Long time no email Marco lol. Last we spoke I had sent you some pictures of the patches on my new little eel. I am just writing you to tell you that I am almost 100% positive they are healing scratches. Although it is "spreading" the eels get into a minor quarrel at least once a day. The reason I am quite sure it is healing scratches/scar tissue is because one time when they got into a scuffle my big eel nipped at the top of the little one's head and the next day he had a spot on the top of his head. I know you said in earlier emails that if they are healing scratches that I do not need to treat it, I just want to make sure that I don't need to get some kind of substance with aloe in it to maybe help??
<No.>
I don't know lol. Even though my big eel is a bully, this little guy is feisty and will sometimes go right up to my big eel and nip him in the face and swim off. It's actually quite humorous because my big eel will not even retaliate.
<I think this is territorial behaviour and would recommend to add more or different caves as suggested in an earlier email, preferably pvc pipes. This species (G. tile) usually does get along with its own kind very well.>
I want to thank you again for your input on the pics I sent you previously, and like always what you suggested "does almost look like healing scratches from bite marks" was absolutely right. As for my earlier nitrate problem, I'm thinking my tank maybe "established" now??? Because I have had 0 nitrates and 0 ammonia for a good almost 3 weeks now so unless something major happens in my tank, you probably won't be hearing from me.
<Sounds good... the water parameters of course. Nitrates probably will rise again slowly with time.>
Once again, thanks for all of your help
<You are most welcome.>
and if you get paid for working for that site, then you need to get a raise lol.
<We do this for free.>
Take care!
<You too. Marco.>

Recently purchased freshwater snowflake eel   9/11/11
Hello all, yesterday I picked up a freshwater snowflake eel for my currently freshwater tank. The petstore told me I might have some problems getting the eel to start eating. Which is fine, both yesterday and today he was very active swimming around everywhere. To my understanding, he was getting used to the tank. Later today he seemed to have stopped moving and started settling in, but then I noticed he was lying on his back. Since I first noticed this it has continued. He still swims around for bits at a time but then he comes back down and when he does he is occasionally on his back or side and I'm not sure why. Is this a sign of illness, is this normal? If illness what can I do? His breathing doesn't seem particularly heavy or fast or anything. But I've had him for a day so I'm clearly not experienced to make such a judgment. I'm hoping I'll hear that he's fine and its just something he'll do but if not please let me know how can I can better care for this creature. Thanks for all your help.
<Hello Aria. The "freshwater" Snowflake Eel is in fact a brackish water to marine species, and the pet shop should have told you this. Indeed, you should have hopefully learned this before buying such a challenging pet.
The most common species traded is Gymnothorax tile but there are one or two others sold from time to time. They all have very similar needs. What you describe -- not wanting to eat -- is extremely common when these eels are kept in freshwater conditions or brackish water that isn't salty enough.
You need at least 25% normal marine salinity, i.e., about SG 1.005 at 25 C/77 F for a young specimen, and for long-term care, about 50% normal seawater salinity or greater, i.e., SG 1.010-1.025 at 25C/77 F.
http://www.wetwebmedia.com/fwsubwebindex/fwmorayart.htm
http://www.wetwebmedia.com/BrackishSubWebIndex/bracsystems.htm
Once settled down, they feed readily on small live foods like river shrimps, and quickly take good wet-frozen and fresh foods such as cockles and tilapia fillet. Minimise the use of Thiaminase-rich foods such as prawns, shrimps and mussels. Do not use feeder fish at all.
http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm
http://www.wetwebmedia.com/fwsubwebindex/fwmorayfdgfaqs.htm
Morays are nocturnal feeders and prefer shady tanks, but given time, will feed during the day. But to start with, place small bits of food in the tank during the evening with the lights out. Don't overfeed.
Cheers, Neale.>
Re: Recently purchased freshwater snowflake eel   9/11.5/11

Hey, I know they are brackish, I should have indicated that prior. When I said it is currently freshwater what I meant was that I was going to acclimatize the tank to brackish once I got the eel.
<Would get this fish into brackish water ASAP.>
I have a couple of dragon gobies in the tank intending it on being a dragon goby/eel tank.
<Dragon Gobies need brackish water, and won't live indefinitely in freshwater. Surprisingly perhaps, Morays aren't good community fish, and often bite fish they can't actually kill. Be very careful when keeping them alongside other fish. Has been done, yes, but "your own mileage may vary".
Would prefer an Echidna species to a Gymnothorax species if that was your aim; Echidna spp. feed primarily on invertebrates rather than fish, so are less prone to biting.>
Sadly, this morning, my eel seemed to have passed, lying on his back not moving. Clearly something was wrong as of last night. I will admit, I am not well versed in tank maintenance but I thought I new enough to be trustworthy with these creatures.
<They are actually very easy to keep. But they DO NEED brackish water, and keeping them in freshwater even for a few weeks DRAMATICALLY reduces your chances of success. The irony is that in marine aquaria most moray eels are considered very hardy fish!>
My Goby's have been in the tank for two months now and they are fine and thriving, as far as I can tell. My question is, what could have gone wrong to cause the eel to get sick and die within two days of purchase, and how could I have reacted to treat the guy?
<Maintained too long in freshwater. Weeks, months at the retailer, and then weeks, months at your home. All too stressful.>
I want another eel but as I'm sure you'll suggest, not to get one until I can resolve my tank issue, so please, any help would be greatly appreciated.
<Do read Marco's piece; it covers everything you need to know. These are really very hardy animals, but upon purchase acclimate to brackish water conditions immediately. No less than SG 1.005, and preferably 1.010.>
Like I said, I thought I did my research but I guess not enough.
<Good luck next time. Cheers, Neale.>
Re: Recently purchased freshwater snowflake eel   9/11.5/11

 I've been going through the posts you've sent, and I appreciate all the help you've been providing so far. If you don't mind, I do have a question or two.
<Sure.>
First off, if I add salt into the tank what are the chances my eel (who is actually not dead but just moving very little to not at all) will turn out alright?
<May help; certainly can't harm.>
If salt isn't enough what else can I do? Further, my understanding was to do a slow acclimatizing of the tank. At what rate should I be increasing the salinity of the tank?
<The problem is the filter bacteria rather than the fish -- these brackish water eels and gobies can acclimate to seawater from freshwater within an hour. They have to, when the tide comes in! But filter bacteria need to be gently coaxed into brackish/marine mode, so you have to go slowly here. If your tank is a freshwater one now, you can raise the salinity to SG 1.003 today without any risk to your bacteria, but after that, you'll need to make small changes weeks or months depending on how big the change. If you look on my web site there's an application called Brack Calc that converts specific gravity to salinity (including grammes of marine salt mix per litre) for any given temperature (25 C being normal). Use this to estimate how much salt to add to your aquarium. For example, let's say you remove 50% of the water in the tank, and replace with water at SG 1.006, i.e., 10 grammes marine salt mix per litre of water. Because you've changed half the water in your tank, you have half SG 1.000 and half 1.006 in the aquarium, for an overall salinity of SG 1.003. Perfect! Use a hydrometer if you have one to check, but weighing out the salt is close enough for this.>
Thank you so much, I have been looking online for tips as well as emailing you, I just really want my eel to live.
<Marco L. has written extensively on these eels, and there's much here at WWM you'll find useful. Good luck, Neale.>
Re: Recently purchased freshwater snowflake eel   9/11.5/11

<PS. the link is:
http://homepage.mac.com/nmonks/Programs/brackcalc.html
It's free, and works on Mac and Windows. Cheers, Neale.>
Re: Recently purchased freshwater snowflake eel   9/11.5/11

Thanks, I found it. I'm pretty sure my eel is officially dead. There are black spots now on his stomach and he's not moving at all. Unless you advise otherwise, I will be removing him from the tank soon. In doing a water change I added sea salt
<Marine aquarium salt, not "sea salt" used for cooking or tonic salt/aquarium salt used in freshwater tanks. Must be marine aquarium salt mix, like Instant Ocean, Reef Crystals, or similar.>
to my tank (as suggested by the store) and the salinity of my tank looks to be just under 1.004.
<Fine.>
I know you said its safe to bring it to 1.003 right away, should I be concerned by this slight elevation?
<No.>
Also, at this point, how much should I be raising the salinity per week or two weeks or whatever?
<The aim would be to go to SG 1.005 in two weeks' time, then leave it there for a few months. After, say, six months, or sooner if your Moray stops eating (a common problem when it isn't salty enough for them) incrementally raise the salinity, for example from 1.005 to 1.006 in two weeks, then 1.006 to 1.007 in another two weeks, and so on. This gives time for the freshwater bacteria to die back and the marine bacteria to multiply. By the end of the year, it'd be nice to have the tank at 1.010.>
And now that the salinity is being raised do you think I can get another or should I wait?
<You might want to leave the tank with just the Dragon Gobies for a couple of weeks just to make sure ammonia and nitrite levels are zero. No point adding MORE livestock if the filter bacteria aren't happy. Go slow. Better to delay adding new fish for two weeks than to buy your Eel tomorrow and end up with a nitrite spike and sick fish.>
Also, I got the pet store to check my water levels and according to them everything is ok.
<Would, at minimum, own a nitrite test kit and a pH test kit, plus the hydrometer.>
Let me know if I'm on the right track and if not how to properly orient myself. thanks!
<Do read, go slowly. Cheers, Neale.>
Re: Recently purchased freshwater snowflake eel 9/12/11

Thank you so much for everything. Your website and what you guys do is awesome and of great help. Just to clarify, the sea salt I got was instant ocean sea salt, I assume that's still ok since you seemed ok with the salinity level my tank is now. Once again, thank you so much.
<Glad to help. Yes, 1.004 should be fine for now, but as/when you get a nice, healthy, fat-looking Moray settled in and feeding, you will want to gradually inch that upwards towards 1.005 for the first 6-12 months, and somewhere between 1.008-1.012 thereafter, or sooner if the Moray goes off its food. These are really very straightforward animals to keep, provided you understand their need for brackish water and a diet with not too much Thiaminase.
http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm
http://www.wetwebmedia.com/fwsubwebindex/fwmorayart.htm
http://www.wetwebmedia.com/morays.htm
Cheers, Neale.>

<"FW" Moray> Eel Project 9/12/07 I tried sending this to Bob Fenner but the e-mail was sent back as having the wrong address. <Ah, yes Trevor... We had to switch ISPs, and no longer have the individual email addresses... I am sending this note to Marco Lichtenberger here, as he is the person who knows the most re this group... of anyone I've had occasion to meet! Bob Fenner> <<Thanks for the kind words, Bob.>> This is Trevor. I e-mailed a couple of queries because I've been having problems with my Gymnothorax tile. I've decided not only to do research on my pet even more in-depth, trying to mimic his/her natural habitat but also do my senior project on it. <<Nice.>> The project will be based on a brackish-water aquarium best suited to moray eels. A species tank. I need permission that you would agree to help me if I have questions. <<No problem. >> My project requires that I will have a community consultant. All you would have to do is answer a few questions if I had them. <<Sure.>> What I need is confirmation that you would assist me in my attempt at this project and educate people about this kind of eel that I commonly find in fresh water at the pet shop (Petco) near my house. <<Okay.>> This would educate whoever reads the booklet. The eels are ordered in at about five at a time. I assume they're quiet popular because usually only one is left at the end of the week. <<Could also be dead/escaped/in the filter. Asked for if all the 'freshwater' moray eels in another shop are actually sold, a clerk answered to me: 'Sometimes they just vanish'. Guess a little bit of education could help here, too'¦>> This is how I purchased mine. One might imagine what the eels would face if the people kept them in fresh water for their entire lives, along with an incorrect tank setup. With all of this comes a form I need filled out. This is as it appears on my paper. Community Consultant Name: Business Address: Zip code: Day Telephone: Other Telephone: Senior Project Topic: Gymnothorax tile setup. <<I am not living in the USA, but Germany, hope that's not a problem. My name's Marco Lichtenberger, contact information can be found on the page www.geo-lichtenberger.de.vu under the point 'Impressum & Kontakt'. I'd prefer, you send your questions to WWM and will assuredly get an answer, so thousands of WWM readers will have the possibility to read about these eels in addition to your senior project. Cheers, Marco.>>

Moray growth cycles   7/16/06 I was looking for information on moray eel growth. I bought a "freshwater" snowflake eel of the Gymnothorax tile variety that I have placed with my albino moray which due to information I have researched I am assuming it is Echidna rhodochilus. The moray "trademark" of opening and closing its mouth to breathe is not happening with my albino. The snowflake is breathing in such a manner and I was told by the owner where I buy my fish food that he was a very beautiful and healthy moray as I had just bought him from another shop and went to get some food from my favorite shop on my way home and showed them. Does anyone know the growth cycles of morays? <Mmm, yes... there are some very nice/useful graphs/charts of time versus SL (standard length) for many species available on fishbase.org> I know they are born in one form called leptocephalus and around 3 yrs. change into elvers. Are there species of moray that do not breath the same way or do they eventually over time grow and change into breathing this way? <Mmm, some "gasp" more than others in general...> They are both approximately the same length except the snowflake is flat on the sides with fins to the tail while the albino is more or less round behind the neck with a tail that comes to a point with no fins which seems closest to the pics I have seen of the Echidna rhodochilus of the various morays I have so far researched. <Mmm: http://fishbase.sinica.edu.tw/Summary/speciesSummary.php?ID=11709&genusname=Echidna&speciesname=rhodochilus unfortunately this is one of the species that does not have "Growth" data on fishbase... Rats! Neither is there such presented for G. tile... These are typically slow growers in the wild and captive conditions (actually, likely less than one percent live a year... due to unstable, unsuitable environment mostly). Bob Fenner>

Re "FW" Moray growth cycles... dead    7/20/06 Thank you for your help but I have some bad news the snowflake died on me and I am assuming he died of starvation along with a possible disease. <... not uncommon... You did (finally) read on WWM re these so-called freshwater eels?> I kept track of the number of ghost shrimp and guppies accounting for X amount to be eaten by my albino and still had more than I should have had. I had a butterfly goby that lived less than 2 weeks and followed similar patterns before the final event and both had skin the same condition after death. I did not see either one eat. The goby I have now has been with me a while. <... this tank is too small... one more time> The albino is a 2nd chance for me as I bought one prior and it died but due to water quality as the aquarium was new and not enough bacteria to break down the nitrate cycle. I tested the water 2 days ago and it tested really well for very low levels of nitrite <Should be zero, zip, non-existent> and I have an ammonia sensor that has not rose above good levels. <I don't like these "sensors"... not accurate> Is there anything else I need to check for? <... read...> I am considering getting another snowflake if possible but am thinking I should wait until I have a much larger tank for the shear reason that I hear when they are moved they tend to stop eating. <Bingo> I had this albino eating within a day of getting him, at least upon visual verification. I feel comfortable with this guy to go 55 then up to larger as the albino is still small and thinner than my pinky finger and he seems so easygoing that eating will not be one of his problems. <Still... need more space> I will need 2 large tanks since the albino is brackish because I also have an ornate Bichir that is right around 2" <Wow! Tiny> now and want to get a ropefish for his tank mate and have recently moved and need to decide if the 2 large tanks will be placed together or separately. If I leave things as they are with the 3 fish in my brackish tank and 55 is good I would have them together but if I need something bigger for the albino I will have them placed in different places. I am planning on starting on getting the 1st tank on the successful sale of the old house to have money to get the best. I appreciate all your help. <Do investigate, plan before purchasing livestock... Bob Fenner> Re: brackish/marine moray growth cycles  7/19/06 Thank you have been a great help so far and I appreciate the quickness of your response. I have read various recommendations for aquarium sizes for eels. I have read that for my albino I would be lucky if it made it to 18" and 24" max and for the snowflake it may reach between 24' to 36". What size aquarium would you recommend. <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwmorayeels.htm and the linked files above> Do you think 55 would be ok with what I have and maybe adding a catfish? <Mmm... no, not likely a good mix> I would not mind adding another butterfly goby and bushfish and maybe if you could recommend some brackish catfish for the clean up crew for a total of 6 fish and which size would you recommend for these? The bushfish maybe to only problem because they may become lunch as they do not get big but the butterfly has venom to protect him. I know that 10 gallon is way too small especially with the addition of the snowflake which I happened upon by shear accident and happened to be not much bigger than my albino except on the sides. I have been keeping extra tabs on water quality and am using a bio wheel filter which I can actually witness how good they are. <Read... keep a close eye on water quality, get a much larger system... Bob Fenner>

Why To Research BEFORE You Purchase - A Perfect Unfortunate Example - Not so FW eel... 06/14/2006 I have a fresh water tank and just bought a snowflake eel. It's a 55 gal. tank and I read on your website that they should have at least 1.005 salinity in the water.   <Please....  learn about your animals BEFORE you purchase them....  I see this going somewhere I don't like....> My first question is that I have many freshwater fish in the tank like a discus, 2 pictus catfish, 2 paradise gourami, a blue and gold gourami, 2 Plecostomus, African butterfly fish, tinfoil barb, Bala shark and two angelfish. <A slightly incompatible mix to begin with - that tinfoil will outgrow the tank and should be in a group/school, so will the plecs outgrow the tank (eventually - they'll be fine for a good long while), the Bala is a schooler that should be kept in a group and which will also outgrow the tank (much faster than the plecs), and the discus, a very shy, retiring animal, really isn't compatible with any of these, save perhaps the gourami and the pictus.  It's unlikely to become bold enough to get enough food in this group.> Will raising the salinity as you say to 1.005 or 1.010 bother or be fatal to any of these fish? <Fatal....  to all....  The snowflake is entirely incompatible in this system.  Your current animals CANNOT tolerate the amount of salt the eel will need as it grows.  It should, as an adult, end up in fully marine conditions.> Secondly how do you go about raising the salinity up to this point 1.005 or 1.010 without stressing the fish. <Forget stressing....  you'd ultimately kill the current inhabitants if you do this.  1.005 for a couple weeks might only damage them, but beyond that will come to a point that they can no longer survive.  Truely freshwater fish are NOT brackish fish, and brackish to marine fish, like your eel, are NOT freshwater fish.  These animals are simply and completely incompatible.> I saw that you told someone not to exceed jumping .002 at a time. So I guess really my question is can you tell me step by step how to raise the salinity in my tank without hurting my fish, <Can't.> and if you could please tell me step by step what I need and how to do this because I will admit I am clueless about this. <Read....  Research....  And most of all, NEVER buy an animal without first learning its needs and considering whether or not you can realistically fulfill those needs.  These are lives....  living things....  please treat them as such.> Thank you. I would really appreciate if you could answer this E-mail as soon as possible thank you. <We answer all as we can.  Wishing you well,  -Sabrina> Eels and Dragonets do not mix'¦.  10/5/05 Hello I'm asking if there is a chance that my 13-inch white cheeked moray eel could have eaten my dragon goby. <I am not familiar with the common name dragon goby; by any chance do you mean a Dragonet or a Mandarin goby? Perhaps (Synchiropus splendidus)?  If this is your specimen then perhaps yes the eel could have eaten him, as they (the dragonets) are slow moving and nocturnal. As for the eel while they usually rely on crustaceans for food, a Dragonet would have been an easy target.> I have noticed that my dragon goby is missing, because he usually wanders around the tank. But the pet store that I bought him from said that the moray would not eat a dragon goby and that my fish was probably hiding. <Eels are predators.>  I have searched high and low for my dragon goby with no sight of him not even fins or anything you find as leftovers to a feeding. <If this fish in question is a dragonet, it's possible that it dies of other reasons. They are notoriously hard to care for with the majority of them starving in captivity.> I think it might have been my moray because of the lack of evidence that my dragonfish would have left like fins scales etc.. I really want to know for sure so I can see about getting a refund on my fish at the store. <Well, good luck with that. Adam J.> <<Mmm, these are brackish to marine animals, Gymnothorax and Gobioides... don't mix. BobF>>

Treating Parasites with Scaleless fishes 7/10/03 I just recently e-mailed you guys (and gals) about the feeding of a freshwater moray eel (I found this in fact, it is Gymnothorax tile).  Now, I have another problem.  My tank came down with ICH.  But, I don't want my moray to die or have a reaction to the medication I use, so which of the following would be better for me to use: QUICK Cure, Ingredients: 25% Formaldehyde, 75% Malachite Green or Maracide (ingredients: Tisaninomethane, Dibromohydroxymercurifluorescein, Aniline green)?  Or something else that I don't have? <Neither are wholly safe for this eel... it would be best to separate the eel from other fishes with a hospital tank and treat accordingly> On your website, you said that organic dyes were poisonous to morays, so is Malachite Green an organic dye?  What about Aniline green?  Is that an organic dye too? <yes to both> Thanx So much for your help, Adam <use straight Formalin in a bare-bottomed tank if you must treat the eel. Best regards, Anthony>

Eel ID (02/24/04) Hi I attached a photo and I wanted to know what eel this is. Mostly I want to know how big will it get like in thickness and length or other information thank you. <Hi! Ananda here tonight... the file name seems to indicate the species: Gymnothorax polyuranodon -- though it does not look quite like other photos I've seen of that species. If you think the file name is not indicative of the species, and to find out more basic info, head on over to Fishbase: http://www.fishbase.org ...just type "Gymnothorax" in the Genus field and check the results. --Ananda><<Is G. tile. RMF>>

"Freshwater" moray eel (03/11/03) Hi, my name is Nate and I've had a "freshwater" moray now for about six or seven months. <Hi -- Ananda here, seeing those quotes around "freshwater" and hoping you do indeed have it in brackish water...> He ate very vigorously for about six and a half months, now he will not eat.  I read a lot on the internet about them and their feeding habits, and it's has only been about three weeks since he last ate. <Do also check our articles/FAQs on these fish: http://www.wetwebmedia.com/fwmorayeels.htm and http://www.wetwebmedia.com/fwmorayfaqs.htm> That's not my main concern though; he now has developed white splotches on one side of his body near his tail.  The water has been tested and seemed to be completely fine.  If you have any idea or advice it would be greatly appreciated.   Thank You. <Could be a number of things. Without specific numbers for any of your water quality parameters, or more info about the tank, it's impossible to be certain what the problem is. I would do a water change on general principle, and perhaps change the tank salinity a bit. Do look for photos of ich and compare to what's on your fish. If you have ich, check the WetWebMedia site for treatment info. If it isn't ich, a photo and detailed tank and water quality stats would help us ID the problem. --Ananda>

Yellow finned eel ID I emailed a while ago about a new unidentified eel I had gotten, and I finally have pictures to aid in the ID process. He's about 8 or 9 inches long, about as wide as a pen or a AAA battery at his thickest point. He eats like a pig, and will come searching around the tank if I pour in a little of the water I used to thaw krill or prawn with. (Even if I stick my fingers into the tank after touching some)  <I think what you have is Echidna rhodochilus Bleeker 1863, "Freshwater White-Cheeked Moray". You can see this animal on our site here: http://www.wetwebmedia.com/FWSubWebIndex/fwmorayeels.htm> I found a white color variant Siderea thyrsoidea (white eye moray), and want to add it to my tank very much, but as it is probably close to a foot in length and maybe as big around as a nickel or larger, but I worry that my little yellow finned beauty will be eaten. <A valid concern. This latter animal will grow much more quickly than your current one> He is currently in a 38, and I can quarantine the white eyed in my (hopefully "eel proof") ten gallon a little longer than normal until I get my 75 up and running in a month or two, but do you think they will bother each other even in there? <Too likely so to suit me> It will be mostly dwarf lionfish; a dwarf zebra lion, a dwarf fuzzy lion, a Fu Manchu, 3(?) leaf fish, a cockatoo Waspfish, and the two eels. I have some shrimp in the 38 with the little guy, and he hasn't bothered them yet. I worry that my current little guy will get too big and eat the white eye moray in time too, since I don't know what he is (hoping not a longtail moray). Scott Michael's Reef fishes book states that white eye morays are not a threat to other eels, and regularly share holes with them, but it doesn't really say what kind of size difference is a safe margin for that statement. I would really like them both, and I worry that because my LFS does not get white eye morays in very often and I can't seem to ever find them on the internet,  <Look up both these species on fishbase.org> that I won't see another one, especially a white one. If I really need to, I can even keep the white eye in my 10 until my 75 is up, then keep him in there and my little guy in the 38, but I'd like to put them together. From the pictures, do you have any idea what my little guy might be? I have more picture, and although they're blurry, I can send them if you need them. Thanks, Valerie Hess p.s. I have already tried fishbase.org and I looked at EVERY SINGLE eel picture they had, but it didn't help. <Mmm, use their "Google Photos" patch on the (double lift click the image on their species identification pages) extended photo/s pages. Bob Fenner>

Just got a "freshwater snowflake eel" Ok at the risk of sounding like an idiot...I just got an eel...the guy I bought it from said it was a freshwater moray snowflake eel, he seemed to know what he was talking about and was fairly helpful...the eel is about 6-8 inches long and in a 10 gallon tank... water is entirely fresh and clean...I got some frozen silversides from the guy I got the eel from and was wondering if this is a good food for him? I threw a few in there, about an inch square cut from the package, I let it thaw and then dropped them in front of his hiding place (a plastic decorative aqua-gator with hollow belly and mouth open) he didn't move for them...I have fish gravel rocks on the bottom and a filter that I got from Wal-mart...I guess I just need to know exactly what steps I need to take to make this a happy healthy eel that isn't going to die on my fiancé.....she will be crushed....please help me....I know that all this is probably in the FAQ but I wanted it personally...if you could send a reply to my e-mail address I would be extremely grateful....thanks a lot.....Mike <you are correct my friend. There is so much to say, and at times we are pressed so dearly for time to try to keep up with e-mailed queries that restating covered topics can be difficult. The eel species needs to be ID first as a true fresh, brackish or marine species. The 10 gallon tank is obscenely small whatever it is. Diet will depend o species again, but is likely to include crustacea (live shrimp (ghost/grass), crayfish, krill, cocktail shrimp frozen). If it seems to respire fast it may need salted water indeed. Please browse articles and FAQs starting here: http://www.wetwebmedia.com/FWSubWebIndex/fwmorayeels.htm Best regards, Anthony>

Gymnothorax polyuranodon Hi Anthony! I <Cheers my friend... and an update: THIS JUST IN: Bob Fenner was recently spotted in a quiet inlet snorkeling with what appeared to be a cluster of helium balloons tethered to his back. When asked what the deal was with the helium balloons, he claimed that he had difficulties securing proper diving gear in this remote location. However, the beer cans strewn about the boat deck and piled up against the helium tank near the tape recorder tell a different story. Look for a Christmas album from Bob this December> just bought a 'freshwater eel'. Noted in past FAQs that you have recommended addition of salt to the water so that they might survive in the long run.  <yes...depends on the species. Many are born in freshwater and venture out to the sea. As such, they really cannot be considered freshwater. Brackish is often better. Your species is actually a more freshwater tolerant animal. Still... some salt would be nice. Do read more: http://www.wetwebmedia.com/fwmorayeels.htm> But if I have Bichirs in the tank will the salt affect them? I read that they are true freshwater species. What about fire eels that are a foot long? Will the salt affect them as well? Do fire eels need salt?? <the fire ell is an "Asian" fish (Sumatra, Indochina, Thailand, etc) that prefers soft, acidic water... nothing like your Gymnothorax polyuranodon. Essentially... one of the two is going to be compromised with regard for pH, alkalinity and salinity to a lesser extent. Still... they are hardy... it may not be much of a problem. I must admit that I wouldn't mix them... but if you do not intend to try to breed them you may be just fine> I keep dwarf puffers in the tank as well. 15 of them actually. They are pretty small at the moment. I heard someone say that if these puffers are swallowed, they will actually inflate such that the aggressor will have no choice but to spit the puffer out. My concern is if the puffer makes it into the stomach and then inflates. Will it kill my eels?  <certainly, but is more likely that their toxic flesh will kill the eels first...hehe> My grouper (abt 12cm) ate one of my puffers and then looked like he wanted to puke it out... But by then he had already swallowed it. He looked pretty uncomfortable after eating the puffer... I am monitoring the situation and will let you know if the grouper makes it through the night! =P <please do> Thanks so much for your advice on medicating fire eels. You are much funnier than Bob. Hahaha... (no offense meant to Bob of course) Well I look forward to your insight once again. Thanks a bunch!! <ahhh... thank you kindly, but you haven't been around Bob enough. He has an enormous funny bone (insert your own joke here). Hehehe. Best regards, Anthony>

Re: Gymnothorax polyuranodon Hi Anthony! Thanks again for your SUPER fast response! <that's what you get when you post a question to someone that doesn't work a real job <wink>> Here are more questions... I am now in doubt as to what species my eel really is. It could be a tile, polyuranodon or rhodochilus. I'm pretty confused now. I want to keep this eel for a long time so I have noticed your recommendation for some salt to be added. However, I noted in your last msg that the polyuranodon is ok in freshwater?  <lets be clear about this... it is more tolerant of freshwater and brackish water than most morays... but it is not ideal by any stretch of the imagination... please do read Bobs articles/archives on this species> So does that mean its not necessary to add salt?  <not even close, my friend... I personally would keep this animal at 1.005-1.010 SG> What about the other 2 species I mentioned above? Do either of them have good long term prospects in freshwater? <1.005 is safe and a recommended bare minimum for the true moray eels> My eel is about a foot long and its roughly the thickness of an index finger. Its not eating yet but I just got it yesterday so...  <I won't be surprised either if it begins to do better when more salt is added. Do use a hydrometer too please> Anyway it looks pretty pale in color (pinkish/translucent) and its mottled with pretty light yellow spots. Sort of yellow... Its design looks something like your pic of the polyuranodon except that it does not have such striking color distinction. It just looks pale. Any idea which one it is? <couldn't say for certain without seeing it and even then...?> Assuming I do add salt. My tank is about 15 US gallons. Its a 2 ft tank measuring 60x30x35cm. Does that mean roughly 1 gram of salt per gallon? Your recommendations in the FAQ is one teaspoon (5gms) per 5 US gallons?  <that will get you in the ballpark, but a glass hydrometer is less than ten dollars and is quite easy to use... highly recommended> I also keep a caecilian and dwarf puffers in the tank. I think the caecilian is able to tolerate 5 gm.s per 5 gallons... Any comments? If I just put 5 gm.s for 15 gallons will it make any difference at all to my moray?  <all will tolerate the low end of the recommendation for certain> Does salt make the water more acidic or basic? <neither...unrelated> I read your site's article on salt. It says,"5.5g gm.s is sufficient for 294 gallons of water." Then the next paragraph says," For simple osmoregulatory stress protection, on an indefinite basis, one can use 1 to 3 mg/L of salt. This would be equivalent to one teaspoon of salt added to 1,453 to 484 gallons of water!" Is this contradictory or does the second Para just refer to 'SIMPLE stress protection'?  <again...you'll want to use a hydrometer and aim for 1.005 to 1.010> What's osmoregulatory stress anyways? =)  <respiratory distress...typically rapid breathing in eels that are too salty or not salty enough> This might sound like a stupid question but I'll ask anyway... If salt can distress freshwater fishes at the concentration stated above, then what happens when the salinity hits 1.010? How will this salinity adversely affect true FW fishes? <easier on the moray but harder on the spiny eels> Will fire eels be able to withstand 1.005 - 1.010?  <the lower end for sure...but not comfortably at the higher end> I assume Bichirs and dwarf puffers can but can fire eels take it? I also read that spiny eels have internal parasites? Is this harmful to them? Should I feed mine some medicine or do I just leave the internal parasites alone? <all wild fish may have them and many captive are likely as well. Do not medicate unless you need to> Do plant fertilizers affect Bichirs or eels (morays and spiny) adversely?  <unlikely in low doses> I have a huge piece of driftwood in the tank. It turns my water a very slight brown. Is this good for my eels?  <delightful for the fire eel...but not natural for the others> Do dissolved plants affect water chemistry greatly? Do dissolved plants and my wood turn the water more acidic or basic? <significantly and more acidic.> I decided to ask more direct questions 'cos I thought that it will aid you seeing as how you have such a unique way of answering everyone's questions. Hope this helps you. Thanks a bunch!!! <thank you for saying so <smile>. Do look into a local aquarium society for networking and shared info too... they really are great places for info beyond the Internet. Kindly, Anthony>

So-called Freshwater Snowflake eel Mr. Robert Fenner, <Anthony Calfo, in your service, my friend> I have a Snowflake Eel that's been swimming on its side erratically from one end of the tank to the other and sometimes resting upside down. I've noticed he's been breathing very rapidly, too. He's about 28" long and lives in a 65 gallon tank, along with seven 2.5" African cichlids (variety) and a 22" white cheek eel.  <the first and most likely problem with your eel is that it is suffering from the extended captivity in freshwater. These so-called "freshwater eels" are only comfortable in freshwater at best as juveniles. As they mature they migrate out to brackish water and some eventually to the sea. This is a common question and problem. The size of your eel and rapid gilling is a giveaway. Do buy a hydrometer and begin a adding sea salt slowly to bring the salinity up by .002 daily (not too fast!) until you reach at least normal brackish water of 1.010 within two weeks. Since you have Africans in the main display... I assume/hope that you are already adding a little salty, eh?> I also keep the feeder gold fish, about a dozen medium size gold fish,  <really...goldfish are an inadequate food item for crustacean feeding eels. Predators forced to feed on such deficient prey often die of complications prematurely. The aquarists often doesn't realize it because the fish seems to be "fine" eating them for a couple of years (but still doesn't reach a full lifespan). Be sure to mix up the diet with great variety of shell-on creatures (krill, plankton, shrimp, crayfish, etc)> in a floating container inside the 65 gallon tank. I changed 20% of the water last Tuesday and he's been eating 2-4 Gold Fishes every other day. I've noticed this change of behavior Saturday evening. Right now I have him isolated in a 20 gallon tank with seven small gold fish (feeder fish). He's not very responsive and tends to lay on its side, sometimes. His breathing tends to speed up at times (average about 49-50 breaths per minute) and slows down (30-32 breaths per minute). I'm a little worried about him. I've had him for about 3 years and I about him when he was 17" long.  Do you know what might be wrong? I've enclosed a picture of him in the sick tank. <yes... please add some salt promptly as prescribed above. Anthony> v/r John Black

Freshwater eel? Not in this case? hello sir <Greetings, Brian. Anthony Calfo in your service> I recently purchased a snowflake eel and I'm getting worried about it it is pale colored and it like to lie on its side, gasping for air it seems, I have 3 African cichlids, a tiger Botia, and a blue crawfish, the eel is about 1 foot long they all live in a 20 high he hasn't looked healthy and I was wondering if you could give me your opinion of what it is I need to do. thank you for you time. Brian Dillon <Brian...your eel is most likely a brackish species. Fortunately, it's tankmates will tolerate and even appreciate some aquarium salt. Add 1 tablespoon per five gallons for starters and only replace it at that dose when you do water changes (not evaporation top off). And look for a picture on the Web (this site and www.fishbase.org) for a picture to identify the species so that we can better help you. Let us know if your eel breathers easier with the salt in the water. Also, test your water quality for any low pH, high ammonia, etc>

Two questions First of all thanks for your last advice and fast response, I will get the pH and nitrite tests. 1) I have a Gymnothorax polyuranodon (freshwater eel) and some times he changes color to a pale one but just happened twice during a month and later he has its original color, is this normal or what could be happening? is eating well, as I see during everyday observation is quite good. <This is normal... seems to have more to do with "mood" than water quality, other external influences... Not necessarily an indication of trouble> 2) I will get a freshwater stingray soon but I can't find written thinks online about injuries caused by the sting and envenomation, what should I do in case of envenomation or being touch by it sting ( accidentally, of course I will take care of this everyday). <Please take a read through the Freshwater Stingray article: http://www.wetwebmedia.com/fwstingrays.htm and Injury piece: http://www.wetwebmedia.com/Wound.htm and we'll be chatting. Bob Fenner> Best regards. Attn. Carlos Gorgon

Freshwater Eel? Hi..! <Hi, Carlos... Anthony Calfo in your service> A few days ago I got an eel, searching at the web found is just one alike and is called lycodontis tile eel, is just exactly the same I have but I'm not sure if it is a snowflake eel (?). <no sir... you have a variegated "freshwater eel", which favors brackish water and if kept in freshwater may be stressed not to feed... but not a snowflake moray eel> This is now 6 inches, small but healthy as I think, it open its mouth sometimes when quite in a place and moves greatly but feeding is kind of concern, since 4 days ago never seen it eating, I tried freeze dried blood worms, <good food, but not likely to be taken> fish flakes ( as pet shop owner recommended) a <that person needs a good book... the only way that eel is going to eat flakes is with a slingshot> and now after more research I set a toothpick with beef heart with just small bites on it but not sure if they were from the eel. <hmmm... perhaps> What do you recommend about this situation?  <try crustaceans (live and frozen)... krill (FD and Frozen maybe)... live ghost/grass shrimp very good> my eel is moving and breathing as usual so I think is healthy, color, eyes and dorsal fin ( from head to tail) is ok. <excellent> What kind of eel is this one.? probably it just eat live fish and need to try. Best regards. <live fish not necessary, I believe. keep us posted, Anthony>

Eel food..? Hi..! searching on your site I found my eel is just the same as: Gymnothorax polyuranodon . <excellent, Carlos... but that is a good stretch from the tile eel species mentioned in your first e-mail. The feeding advice stays the same... but did you buy the eel in fresh or saltwater. If saltwater, disregard the history mentioned in the last e-mail. Best of luck to you, Anthony> Thanks.! Attn. Carlos Gorgon

Re: ALL CAP'S and stocking cichlids and eels what's wrong with all capitol letters? is this better?  <Yes, thank you. Much easier to read... an aspect of "netiquette"... rules of polite society> am not shouting. ok. (lol) can I put a freshwater eel in a 55 gallon tank with a red devil and a green terror.? <Mmm, not really a good idea... "the" freshwater eels are too slow, blind to compete with such "go-getter" cichlids. Please read here: http://www.wetwebmedia.com/fwmorayeels.htm Be chatting. Bob Fenner> Gregg

Freshwater morays Hi Bob, I have been reading the FAQ on freshwater moray eels and was wondering if you could help me out with a query of mine. A friend of mine recently acquired 3 freshwater morays directly from a wholesaler. He was informed that they were a freshwater species and that the specimens were actually bred in captivity in freshwater. <Really? Hmm, have just this last week finished spiffing up this section of WWM... no Morays (Muraenidae) have been spawned, reared in captivity... the larval history phase, the leptocephalus, is very problematical...> He does not have the Latin name but we believe them to be Echidna rhodochilus and they range in colour from a peppery speckle to whitish. <Yes... wish I had better pix of the white and black geographic "races"... very beautiful> I am surprised to hear that they were bred in freshwater but apparently this is the case. They are about 4" long and currently being housed in a 20 gal aquaria where they are doing well and feeding on river shrimp. <Neat> Due to the eventual size and conditions they require he has offered them to me as I have a 150 UK gal brackish tank housing Figure eight and green spotted puffer fish. I am interested in taking these fish but am wondering if my current tank inhabitants are suitable tank mates for these morays. The puffers range in size from 1-4 inches. <I suspect there might well be trouble with the Puffers both biting these tiny eels and consuming all their food. I would at least put a serious barrier/divider between the front and back of a section of your tank to keep them separated> I look forwards to hearing your reply! Many thanks, Kris Graff <Be chatting. Bob Fenner>

Re: freshwater morays Hi Bob, Thanks for the info and the quick reply! I was wondering if it would be an option to grow the eels on in a species tank and then introduce them to the main brackish tank with the puffers when they are at a decent size. Would I still see problems here as regards to the eels catching food? <Possibly... the Puffers might be able to be trained to accept food in one corner, the eels the other...> I will send you some pictures of the eels as soon as possible. My friend has three of different colour phases, the white is indeed very attractive. Once again, thank you for your help, Kris <Be chatting my friend. Bob Fenner>

"Freshwater " moray eel Mr. Fenner, First, like everyone else, I have to thank you both for your excellent book and the responses you post on WWM. They were both very helpful last year when I set up my first reef, which continues to thrive thanks to your advice. <You are certainly welcome. Thank you for the acknowledgement> I am writing to you regarding the eel that is commonly sold as "freshwater snowflake moray," which I am using as the centerpiece for a brackish tank. I recently purchased one at 18" that has turned out to be a fantastic fish. (Just recently came off its hunger strike...big relief for me!) <Ah, yes> First, has the scientific name for this eel changed? I see it on WWM referred to as Gymnothorax polyuranodon, but I have seen it referenced elsewhere as Echidna rhodochilus.  <Hmm, well this is a valid name for one of the "marine/fresh Moray species": http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID= But the former is also freshwater and a valid species: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID= And there are a few others that are occasionally imported for aquarium use... So, both do come to ornamental aquatics through the Philippines, but are separate/different species.> Second, I have found reliable information on this animal hard to find. I have read the synopsis here and on Fishbase, as well as on Ruben Tolen's brackish site, but I have found little else on the web. I am primarily confused on the salinity this animal needs to be kept at as an adult. 1.010 is about what/where I've seen them kept by the trade... as juveniles. The Echidna I suspect should be kept in NSW, Near Seawater, conditions as an adult> I always see it referenced as a brackish fish, but reliable responses from other aquarists on AquariaCentral and FishIndex suggest it requires marine conditions as an adult. I am prepared to provide for it either way, but I would like to know what environment will be best for it. Thanks for your time and your expertise, Jason <Actually either or both of us need make a trip down to a large/r college library here (unless you have BIOSIS/Zoological Record access at home/office... Go back to Fishbase.org and click, follow under "references"... and if you have time, inclination, to the library you go, and have a reference librarian show you how to do a computer bibliographic search. Like: http://wetwebmedia.com/litsrchart.htm Be chatting, Bob Fenner> Re: "freshwater " moray eel Mr. Fenner, Thanks for the quick reply! The freshwater moray that I own looks more like the echidna rhodochilus from these pictures, as does the animal labeled as Gymnothorax polyuranodon on WWM: http://www.aquariacentral.com/species/db.cgi?db=fresh&uid=default&ID=0580&view _records=1 Does Gymnothorax polyuranodon display enough color variation to account for this difference in pictures, or is the photo on WWM (or AC) possibly mislabeled? <Don't know about the range of color, patterns in this species... all the ones I have seen have been rather bland... if these were indeed G. polyuranodon... But do know (for sure) about the possibility of mislabeled images identified by myself! These are definitely due to error.> Also, I happen to be student at Virginia Tech, which unfortunately doesn't help as our library does not have the text cited for rhodochilus on Fishbase. I will look into Interlibrary Loan and see if I can get lucky...I will let you know if I find out anything interesting. Thanks again, Jason <Yes to the interlibrary loan... Do check to see if you have BIOSIS on campus. Bob Fenner>

Freshwater Moray Eels I really appreciate the time that you took for this site. <Ah, you're welcome. It was made for you.> I would like to buy a fresh water Moray Eel. I guess I need some help and no one in pet stores really know anything about freshwater. I am going to put it in a 75-100 gallon tank. What kind of sand should I put down?  <Something fine/r... and calcareous. Please see the "Marine Substrates" section and "Moray Eels" under the Marine Index (the freshwater species are touched on there)> Is possible to order a fish through the mail? <Certainly> Can I feed them gold fish? And better yet how about a book on fresh water moray. This would really help. <Not really goldfish, but other live or frozen/defrosted meaty foods. Take a look at the WWM site cited, then fishbase.org then your search engines under "Freshwater Morays"> Thanks, Michael <Be chatting my friend. Bob Fenner>

Re: Freshwater Moray Eels Thanks for getting back to me. I have called all over the place in Virginia looking for a "fresh water moray eel' I have had 0 luck! Do you know of a place that I could order one through the mail or call. <Take a look at the livestock etailers listed on our site (www.WetWebMedia.com) Links Pages> I have also had no luck looking for a book. <See the "Moray Eels" section on the WWM site> I figure that I will get a 75 gallon tank with heaters that will keep the tempter a 70-80.{F}. I will have a 2 caves in it so that it can hide and the sand that you recommended. I will buy a power filter. Do you think that I will need a skimmer? <Probably not a skimmer if you are going to try keeping the water entirely fresh... do take a look through Fishbase.org under the term "freshwater moray". Bob Fenner> Thanks again, Michael Davis

Freshwater snowflake moray I got a snow flake about 2 weeks ago and it wont eat I've tried all sorts of food (Tubifex worms.. live...crustaceans..) please help ... please mail any info you might have thanks <Do have patience... these Eels frequently go on food strikes when first moved... do keep trying various meaty, live foods, including smaller earthworms (like those you can dig up, or buy at bait stores), and if your other fishes, plants et al. can tolerate it (they should), do place a teaspoon per ten gallons of non-iodized salt (ice-cream, kosher, pickling...) in this system... should help stir appetite and act as a general cathartic. Bob Fenner>

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