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.> 

Brackish fish compatibility   12/25/11
Hi, my name is Sandra. First of all, merry Christmas :) and thank you for all your help.
<Merry Christmas to you, too.>
I have purchased 3 Gymnothorax tile (between 12 and 16 inches) for my husband as a Christmas present. They are in a tank with a violet goby (Gobioides broussonetti, sorry for bad spelling, at 10 inches). We also have a figure 8 puffer in his own tank. I was curious if we could keep all of these critters together?
<Very, very difficult to say for sure. The Figure-8 puffer is small enough to be viewed as food by the Morays, so that's risky for sure. On the other hand, Figure-8s can be nippy, and they aren't good companions for Violet Gobies because of this. Violet Gobies are big but completely peaceful filter-feeders and substrate-sifters, so mostly get along best with small, inoffensive fish such as Guppies. Moray eels don't always coexist, but if they do, they should get along okay with the Violet Goby, provided all these fish have suitable long burrows (PVC pipes are ideal, perhaps with gravel or shells siliconed to the outside to make them look more natural, then half-buried in the substrate).>
All are in brackish to marine conditions and yes, we purchased all to get them out of freshwater and bad conditions.
My other question is what foods are safe for the eels?
<Variety! A good staple would be lancefish (from the pet shop, frozen) plus tilapia fillet, cockles, and, in smaller amounts, krill, mussels and prawns. Occasional offerings of earthworms, bloodworms and mosquito larvae will be fine. Ideally, use a vitamin supplement because frozen foods lose some of their vitamins; you can buy vitamin supplements in stores catering to marine fish, where the vitamin problem tends to be most acute (fish that eat flake or pellets don't need vitamin supplements, but not all marine fish routinely eat flake food).>
We have two eating frozen Silversides and krill. Once a week they get feeder crayfish.
<Fine.>
The mollies that were originally in the tank quickly became food except for one (her name is Lucky!) What else can we add to their diet to make sure they're getting the proper nutrition?  Thank you again for your time and quick responses to previous questions.
<Do read:
http://www.wetwebmedia.com/fwsubwebindex/fwmorayfdgfaqs.htm
http://www.wetwebmedia.com/ca/volume_3/cav3i3/Dragon_Gobies/DragonGobiesart.htm
And follow the relevant links at the top of those pages. Good luck! Neale.>

Re: ALL CAP'S and stocking cichlids and eels what's wrong with all capitol <capital> 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

Eel Won't Go With Cichlids   5/27/06 The pet store recently advised me that I could put a snowflake eel into my 55 gal tank with cichlids.  He is about 8 in long-when I introduced him to the tank the cichlids started to nip at him almost immediately.  He had moved into a rock formation and has stayed put-but the cichlids continue to go in and nip at him  Was I misinformed-should I remove him from the tank (do you think the cichlids will kill him)  Please advise. < Yes the cichlids will kill him. Take him back for a full refund.> The cichlids are African cichlids about 2 in long-I think they may be spawning -they are nest building. Thanks, David < The breeding cichlids makes no difference on the eel. They were trying to eat him.-Chuck>

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.  Truly 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>>