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Long time, no email....another eel problem 10/16/12
"Freshwater" Moray Eel Two Questions, fdg., sys. 4/1/12
<Thanks for your kind words.>
I have been maintaining my brackish water tank using all of your incredible advice. Well on to the questions....First off I have a 40 gallon brackish water tank PH is at 8, nitrates and ammonia levels are all normal and temp is kept at 80 deg F. Started off by having gravity level at 1.010, but have slowly over time raised it to it's current reading of 1.021. In the tank I have a "freshwater moray eel" or as you refer it to a Gymnothorax tile, a green spotted puffer and a "freshwater" flounder/flatfish.
<Not the best tank mates, these eels can become really incompatible when growing up.>
I first purchased my eel about two months ago and of course he went on a hunger strike, but after raising the salt levels to 1.021 the eel has been eating. My concern is he is eating like crazy! He accepts food by tweezers and his diet is consisting of freeze dried krill, shrimp, muscles, silverbacks, ghost shrimp and tilapia (I like to keep his diet varied). I read on your site that juveniles tend to eat every other day and adults eat twice a week. My eel eats two times a day each time taking two different foods. He doesn't seem to just be stuffing himself because when he has "had enough I guess" he goes back into his cave. Is this normal for him to eat like this??
<Oh, that's what I often ask myself about some people.>
I feed him at a specific time in the morning and at night and he is readily waiting for me, sometimes barely letting me get the food in the tank. When I first got him (assuming its a he) he was very skinny about the circumference of a dime and 11in long. Now he is almost the circumference of a nickel and 13 in long. My question is, should I keep his feeding habits the same, or if not what amount he should eat?
<You offer much more to him than nature does in my opinion. I'd feed significantly less, about the size of the eel's head per feeding. Feeding every other day is sufficient. There are some reports on the negative results of overfeeding moray eels, e.g. by P. Purser in the TFH book and there are examinations of eels caught in nature showing they don't eat every day (some larger species only once per week or less.>
My next question is, I read that when juveniles, the eels live in brackish water and eventually move to full saltwater when older.
If this is true, when should I convert to a full saltwater tank?
<It's easier to maintain, because you can use a skimmer, live rock. You've almost reached marine salinity, so I see no reason to not convert to full saltwater.>
Thank you so much for your time and I look forward to hearing from you!
<Also see: http://www.wetwebmedia.com/ca/volume_4/V4I2/Freshwater_eels/freshwater_eels.
htm . Cheers, Marco.>
Re: "Freshwater" Moray Eel Two Questions 4/1/12
Thank you very much for responding so quickly!
I am going to reduce my eel's food starting today. Do eels beg?
<If by begging you mean that they expect to get food from a known source: yes. In some areas moray eels accumulate below the nets of large offshore fish farms. Every time the fish within the nets are fed, the moray eels come out to get their share, which falls through the net.>
Lol, because that is going to be the hardest part in reducing his diet. He literally "begs" by sticking half of his body out from his cave and faces towards the surface waiting for me to feed his fat butt when I come in the room every morning. In regards to his tank mates the green spotted puffer and the flatfish, so far the eel is very accepting of them, but I will watch as he gets older to see if he acts aggressively towards them. Thanks again for all of your help!
Gymnothorax tile eating shrimp
My eel eats 2 frozen shrimps every week. Today I was feeding him a shrimp on a kebab stick when he ripped the whole shrimp of the stick and swallowed it whole! Usually he would only bite off a bit and eat the rest later. After swallowing the shrimp I could clearly see the shrimp inside of him (A big bump formed inside him - about in the middle of his body). He swam around the tank a few times and then retreated to his cave. I went back a few minutes later still seeing the shrimp inside him. Is this okay?
<Yes, no problem, when it can be swallowed, it's apparently not too large.
Try to keep the diet more varied:
Thank you Niki
Brackish Water Snowflake Eel in Freshwater; sick,
FW Moray eel behaving strangely
Gymnothorax tile feeding problem
Re: Gymnothorax tile feeding problem
True Freshwater Moray found? Impossible? -- 02/06/09 Hello, Hello Moray Experts :) <Hi Trevor.> Trevor here with some fairly interesting things to discuss, it seems, perhaps, as supported by about.com and Fishbase that there is, perhaps a true freshwater moray? Even the About staff seem to have been confused at first but say it's confirmed. If not it seems they should be corrected ASAP because it was very misleading if they're wrong. <Feel free to do so, the text is around since a few years.> The eel in question is Gymnothorax polyuranodon. <Ah'¦ know it, kept it.> Supposedly they've dug deep into their research, whatever that may be, and found that this moray lives primarily in fresh water. It seems suspicious, as I look over to my Gymnothorax tile next to me and think that they must be confused. Certainly, it's a brackish fish, as they list it as venturing into brackish water, right? <G. tile mostly occurs in mangrove swamps with high salinities or 100% marine salinity during the dry season. It also travels up river mouths, possibly to get rid of parasites or to breed. In captivity it does best in a marine tank.> I found all this somewhat interesting and wondered if it could really be true. One more question, would you happen to know the pricing on this "Spotted Freshwater Moray?" <The ones in Europe cost the equivalent of about 60-80 USD in the stores, they only available every few years.> Even if they are brackish, I've been thinking about getting another moray. These are quite attractive. Fishbase: http://filaman.ifm-geomar.de/Summary/SpeciesSummary.php?id=17227&lang=English <I exchanged your link, because the English server seemed to be down when I tried.> About.com's "Freshwater" Moray list: http://saltaquarium.about.com/cs/eelprofilesindex/l/blfweels.htm Thanks, Trevor <Trevor I know the text at the site you linked to and have most of what is known to science re this eel as well as own experiences and reported experiences of others from the pet fish trade. As you can see G. polyuranodon occurs in various habitats from freshwater to marine, was found as far as 30 km away from the coast. It's even speculated this eel could be catadromous (living in freshwater, but travelling to the sea at breeding time), you can call it an euryhaline fish. With regard to its captive care, I've tried everything from freshwater to marine and have to state that they did by far the best in a marine tank, while the ones left in freshwater at the shop did much less well, refused to eat with time, looked much less vibrant. So, G. polyuranodon does much better in freshwater than its G. tile cousin, but still at some point of care you will not be able to avoid salt completely without endangering the health of the animal. But it is a great pet and truly justifies the additional costs related to a marine setup. Have a look at the WWM articles on freshwater moray eels: http://www.wetwebmedia.com/fwsubwebindex/fwmorayeels.htm and http://www.wetwebmedia.com/fwsubwebindex/fwmorayart.htm No pet moray without salt. Sorry. Marco.>
Re: True Freshwater Moray found? Impossible? II, fdg., sys. -- 02/07/09 Hey again Marco, <Hi Trevor.> Well, a question about the other eel, (not G. tile, but polyuranodon). How hard is it to get them to eat? <Just the same a G. tile or other morays. May take days to weeks, but given pristine water conditions and salt they'll eventually start eating. G. polyuranodon is a little more shy, and although they may become longer than G. tile, they are even slimmer and remind me somewhat of ribbon eels.> My G. tile eats just fine in his brackish water setup and even comes out to investigate his tank at night. ...and one last thing. Is it normal for a G. tile to bulk up? <Yes to some extent about once a year I notice a slight gain of girth. I guess that may be prior to their breeding time. With age they also become a little more stout.> I've seen the small, skinny ones all the time though, I'd like mine to pick up some weight. He does eat regularly, but he just does not eat all that much. It's as if he's set to eat a predetermined amount every day. <Just don't overfeed. This can cause liver problems in the long run. If it does not want to eat anymore, it's okay.> He's healthy, a deep gray/blue color with tiny bright-yellow spots on him. The mollies don't stand a chance, and the bits of squid, octopus and silversides are relished as well. I try and rotate his diet to give him enrichment and some good nutrition. I think I'm doing everything correctly so far. <Yes. You can add fish vitamins once a week to the frozen foods.> The eel is very responsive to food and is always looking out across the room from his PVC pipe that's buried in the gravel. Speaking of gravel, is it better to keep them on sand or gravel? <Does not matter.> The guy at the fish-specialty store told me morays prefer sand to gravel but... I always see them in reefs where there's no sand, and they certainly don't hang out in the open all day although I do know from videos online that they come out at night and hunt for fish among the rocks and coral. <As G. tile comes from mostly mangrove swamps and estuaries, a fine grained substrate like sand does resemble its natural environment more closely. However, for captive care it does not matter, the usual aquarium gravel or even better crushed coral is fine. Just avoid substrates with sharp grains. Personally, I prefer sand for the moray tanks, too, for the purpose of natural denitrification, which takes place in well populated marine sand beds. As a side note, many moray eels do not inhabit the reefs, but sea grass beds, gravel fields and muddy bottoms.> Any further advice? Thanks, Trevor. <You seem to be doing very well. Marco.>
Feeding a freshwater moray eel 06/14/08 hi, first of all what a great site!!! i brought a moray ell 3 weeks ago. he is in my freshwater 30 gallon tank that has been up and running for about 2 months with some small loochs and sucker fish. The ell is 12" long and looks a bit like a Muraena helena. he has the sticking out nostrils and is coloured light brown/beige with little yellow/white spots on his body with a small fin along his back. do you know what type of ell this is? i will try and get a picture from my friends camera. The other question is about him feeding He has been in the tank now for 2 weeks and seems happy. he comes out when there is no one watching and when the light is off but most of the time sits in his hiding pot. i have put live shrimp in the tank over the weeks and they have all gone but my loochs eats them so im not sure if he's been eating, as i have never seen him eat. he's not interested in shrimp meat, or dead dilles. im wondering if he's ok or if he needs something else to eat thanks a lot chris <Hello Chris. The so-called 'freshwater moray eels' are in fact brackish/marine fishes. There are several species in the trade, but by far the commonest is Gymnothorax tile, a pinkish-brown species covered with tiny yellow spots, and that's the species you likely have. They do not do well in freshwater permanently, and most simply die after a few months. Given morays can easily live 10+ years when maintained properly, there is absolutely no justification for keeping them in freshwater (or for that matter for retailers to sell them as freshwater fish). A common symptom of insufficient salinity is a lack of appetite, which is what you are seeing. At minimum, you need to maintain them at SG 1.005 (about one-quarter normal seawater salinity), and many would argue (myself included) that at least half-strength seawater (SG 1.010) is required for permanent success. Obviously they cannot be combined with loaches or other freshwater fish. Moray eels are primarily nocturnal and hunt by smell. This means you can't combine them with more active nocturnal fish. Some specimens remain good community fish their entire lives, provided they are combined with tankmates of equal or larger size. The best approach seems to be to keep them either alone or in groups. Others become more aggressive and will bite bigger fish even if they cannot kill them. Do read Marco's excellent article on these fish, here: http://www.wetwebmedia.com/fwsubwebindex/fwmorayart.htm Once you've digested that, review how to create a brackish water aquarium here: http://www.wetwebmedia.com/BrackishSubWebIndex/bracsystems.htm Because eels aren't terribly active, you don't need a huge aquarium; 125 litres/30 gallons is ample for a single specimen, particularly if you have high capacity filter and do regular water changes. At high salinities, a protein skimmer will help a lot too. Hope this helps, Neale.>
Gymnothorax tile eating questions, Proper food for Gymnothorax tile -- 06/12/07 Hello! <Hi Amanda.> I just love your website!! So much information! <It's great you like it.> I have a wonderful Gymnothorax tile. I have had him (I'm not sure how to sex them, so I just call it a him) <Will compose an article on sexing moray eels in the coming months.> for about 2 years now and he's doing wonderful. He has grown a lot since I first got him and is a joy to watch him at night. <Sounds good.> At the moment he has a selection of ghost shrimp, rosy minnows <not appropriate feeder fishes.>, and a few guppies. He has the tank to himself except for feeder fishies. He has his own awesome cave that he sleeps in all day. And other rock structures, plants <freshwater or brackish water? Hardness? If fresh, are you sure it is a G. tile? 2 years in freshwater would be an exceptionally long time of survival for this species.>, and tubes to hide in when he's out at night. He likes to hang out in one of the tubes and wait for fish to swim in. He's a lazy hunter sometimes. <Sounds familiar.> I have 2 questions about feeding him. 1) Should I leave the smart fish in the tank? It seems that with every sacrifice, a few fish are smart enough to learn that the eel cruises the bottom of the tank for food and so they stay at the top, safe and uneaten. The eel tries his best to eat the little buggers but they are just too fast for him. Some have managed to stay alive long enough to grow big enough that the eel isn't interested in them anymore. Should they remain in the tank or be removed and "freed" to their own tank? Is it bad I feel like the Emperor of Rome, deciding if the gladiators (fish) die or be set free? Hehe <Removing them would be good to avoid overfeeding, which is a common reason for the short lifespan of captive moray eels. Like humans they tend to eat more than they need. If you enjoy the fate of the feeders is your own decision. I prefer feeding frozen food and use feeders only for freshly imported specimens or to train difficult species such as Rhinomuraena quaesita and Pseudechidna brummeri. I consider frozen food to be more simple and safe. See this very good article by Neale: http://www.thepufferforum.com/forum/library/feeding/feeders/ on the ethics of feeding fishes and appropriate species. See http://www.wetwebmedia.com/ca/volume_4/V4I2/Freshwater_eels/freshwater_eels.htm for proper care for G. tile. I'd stop feeding minnows and vary the diet with sea food.> 2) I have been reading the eels prefer crustaceans <Some species do. G. tile eats almost anything mobile including most crustaceans.>. I did at one time attempt to keep a larger shrimp (name escapes me atm) in the tank. That lasted all of one night. Eel gobbled that guy up, even though it was fairly large. My question is, would feeding him crayfish be okay? <Yes, as long as the diet is varied.> Eel is about 16 inches long (I'm not brave enough to try and actually measure him, nor do I want to stress him out trying to) and about as big around as a quarter. I am worried that the crayfish could hurt him or the eel get hurt trying to eat the tough shelled guy. <You could freeze the crayfish before feeding it to the eel.> If it is okay, what size range would be safe? Of course, the smaller the better, but what would be considered too big? <About the size of the head of the eel (1-2 in.) should be safe. Larger ones could try using their claws, although I think they would not be able to cause serious wounds as long as you don't throw some lobsters in there.> Thanks so much! Amanda. <Hope that helps. Marco.>
Eel eating habits 9/23/06 I have a brackish water moray eel that is albino <Unusual> that has been doing very well. I have had him for about eight months now. The only concern I have with him is he is beginning to eat more than he has been. Can he eat too much? <Mmm, yes, possible> I place some guppies and ghost shrimp in for him to eat at his pleasure. He has been doing well except recently he has been eating more than usual. Is this abnormal or something like a phase eels go through? <Can't say> I have added a butterfly goby and a few other fish but they are too small for guppies as food and the only other fish capable of taking guppies was my leopard bushfish and he died (I believe he may have been stuck by the butterfly goby as one of the two I bought was also found dead). I have watched my eel gulp a shrimp or two then continue to go after guppies and just keep trying over and over. He used to not eat like this before. Is there any reasons I have given here or that you can think of for such a voracious appetite? <Mmm, no> One last question on eels in general. I have heard that all eels go to the Sargasso Sea to spawn. Is this true or is it a specific species that does this? Thank you <Anguilla rostrata solamente. BobF>
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>
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>
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 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
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 fiancÃ©.....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>
Freshwater moray eels... actually brackish 11/18/05 Hi- I have a 180 gal. tank that I've had for a long time. My fish have been thriving for many many years. Three years ago I felt really sorry for two "freshwater" moray eels in a shop in a tiny tank. They looked terrified and had no shelter. I know from scuba diving that they like to stay in caves or overhangs and I could tell these guys were miserable and terrified. I went ahead and bought both of them, then went on the internet to see just what I needed to do for them. I upped the salt in my tank to one tablespoon to 5 gallons. My other fish are doing fine after three years. I have Jurupari, one mono, and one "fat" goby. So the eels have been great and happy-- they each have their own cave, they were eating calamari, shrimp, krill, salmon and smelt. <Me too!> I know they can go a few weeks without food, which they do sometimes. They are off the food again. The problem is that for the last two and a half MONTHS they haven't eaten, they go into one cave together (which they NEVER would have done before), one has a swollen throat, the other has a lump on his chin, <Likely goiters... from a lack of iodine (can, should be administered exogenously) and the cumulative effects of life in too "fresh" water> and they are just acting very strange. The goby is looking grayish (he's a dark brown normally) and his eyes are a little cloudy. The eels and the goby won't eat and the other fish seem to be ok. The water tests are all fine. I've upped the salt to one tablespoon to two and a half gallons of water and upped the temp to eighty five. A week later, they still don't look good. If you can help me with this I would appreciate it greatly. Also, do you know how long "freshwater eels" live? <Years when kept in brackish (spg of 1.005-1010) to marine (as adults) water> Thank you very much-- Dana Mardaga. <Bob Fenner>
"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>