How to keep your moray eel, Echidna rhodochilis, alive with pictures

Origins: Most freshwater moray eels come from the mouths of rivers where they pour into the ocean. Most of their cousins live in the oceans. These guys come into areas where fresh and salt waters mix – brackish water.

Name Origin: The freshwater morays look just like the sea-living guys (with a smaller top fin). People also call them snowflake eels, snow-spotted eels, and psychedelic eels.

Water Conditions: In plain old tank water (with no salt) they soon grow a coating of slime. Then they quit eating. Then they die. Add plenty of salt. They can stand from ¼ to ½ sea water. Huge variations in salinity don’t bother them as long as you keep their water clean. Give them at least two teaspoons per gallon.

Appeal: Obviously people like these guys because they look like the feared moray eels we see attacking deep sea divers in the movies. (Those attacking eels are professional actors trained to show off when the cameras come on.) Do not expect your freshwater moray eel to bite you or larger tank mates. However, they will snap up smaller tank mates. And they can bite YOU, although we’ve never heard of that happening.

Size: Theoretically, these moray eels grow to 36 inches. However, if you grow yours to18 inches, you’re doing pretty good.

LA
He jumped. We do not recommend carpet as a substrate. It irritates their skin.

Jumpers: Any eel-shaped fish will stand on its tail and bail out of uncovered tanks. Moray eels get large enough to nudge a fairly heavy cover off their tank.

Hiders: Freshwater moray eels need a hiding spot. An upside-down clay flower pot with a notch in it does a serviceable job. Tubular ceramic pieces look better. You’ll often see them poking their heads out as though waiting for prey to pass by (just like in the movies). You can keep them together if each has its own hiding place. Or, lean a piece of slate against your front glass for a full frontal view 24/7.

Foods: Moray eels readily eat live foods – guppies, rosy reds, goldfish, ghost shrimp, and worms. Most will convert to frozen foods. We’ve never seen any of them eat flakes or pellets.

Tank Mates: Keep moray eels with brackish water fishes larger than their mouths but not big enough to beat on them. Obviously, they will eat bite-size fishes Good mixers include larger black mollies, sailfin mollies, and chromides. Bull sharks should mix well also but really hog the food. Leaffish, tiger fish, and gobies also work.

Breeding: Never say never, but don’t waste your time. We’ve never heard of anyone breeding these moray eels. (Or even trying to breed them.)

LA
Once again, a piece of slate against the front glass gets your moray eel out front.

Substrate Choice: Darker gravels will darken your moray eel. Silica sand makes a satisfactory substrate except with under gravel filters. Use a power filter or sponge filter when you provide a sand bottom. Make your sand layer very thin.

Plants: Because of their high salinity needs, you won’t find many plants that can survive with moray eels. Use plastic plants. You can try Java lance fern. Morays like lots of cover.

Disease: Putting plenty of sea salts in their water will help prevent bacterial slime – their main threat.

Filtration: Moray eels like clean water. Do not overfeed. Use good aeration and frequent water changes to help keep their water clean and healthy. LA.

Robbie Dick, March 10, 2007
When I was about ten I purchased a Freshwater Moray Eel. I did some research and soon found out that there is no such thing as a freshwater moray eel. All the Eels you have pictured are called Common Dwarf Moray eels, with the exception of the very first Eel, which is not a moray (no nasal holes or heat pits on their detachable Jaw). They are born in streams of freshwater but soon must travel into the oceans to survive. They can survive in brackish water for extended periods of time but much prefer full salinity. With my Eel I can stimulate her reproductive cycle to lay eggs by decreasing the salinity (simulating travel up into a stream). I have tried twice to introduce a male to fertilize the eggs, but both times I have tried
the added eels turned out to be females and laid eggs on their own. I think if you were to inform people that these eels were meant to be in full saltwater they would have a much better chance of them surviving. Thank you.

A: Good info. I'll add it to my page. LA

Ryley McCormack, Cranbrook, BC, January 11, 2009
I have read your article about freshwater moray eels and it says they're brackish, but I have been keeping mine in pure freshwater and it's doing fine, so I just thought I should let ya know.

A: I'll add your comment right below the communiqué from Robbie Dick that says they need 100% seawater. LA

Jake Hawk, Waterloo, IA, October 5, 2009
Hey there, just wanted to toss my research in the ring on the moray eels commonly sold as "freshwater." The part-time fresh-brackish-marine deal is the true life cycle of these great fish, and while they can survive in purely fresh water for an extended period of time their eating habits, growth and overall behavior will be affected.
I've attached a few photos of my moray in his 55gal. He's the largest I've seen so far at 26" (!). I couldn't get him to stretch out and swim for me this evening so the pictures don't do much justice. I know he supposedly has a good deal of growing yet to do but it's rarely achieved in captivity. Thanks for the chance to add my thoughts... and...well.. show off

JH
Note the two feeder goldfish (for perspective). LA

A: Thanks for "showing off." I'll add your report to our moray page. LA

Jennifer Harrison, January 8, 2011
Hello -- I came across your article about "freshwater" moray eel care tonight, and thought I'd add my experience. The eels you pictured (aside from the top one, I have no idea what that is but it is not a moray) are all Gymnothorax tile, more commonly called the "freshwater snowflake" eel. These eels are born in brackish estuaries and river/stream mouths of varying salinity, and as they grow they make their way out to the ocean where they live life as adults, only returning to fresher waters to reproduce. 14 months ago I took in a pair of G. tile from the manager of a Pet Supermarket in Madison, Wisconsin. He's a friend of mine and told me he got these eels in as "freshwater" eels but they just weren't doing well in their freshwater display system. I told him they need brackish water at minimum, and they would die if he kept them in freshwater. He gave them to me for free to get them into a better situation. Sadly, the lighter colored one did not survive more than 48 hours. She was too skinny, weak, and pale. The other flourished, and over a 2 week period I slowly raised the salinity in his tank, and acclimated him to full marine conditions. I moved him into my saltwater reef, where he has lived for over a year now. Specific gravity is never below 1.024 and he has done wonderfully. He eats raw shrimp, raw squid, and thawed silversides, every other day. He will also explore along the sand amongst the rocks and munch on pieces of krill, plankton, mysis shrimp, and other tidbits he finds leftover from feeding the other fish. He cohabitates with an 8" true snowflake moray, a large yellow tang, a large mated pair of gold-stripe maroon clownfish, and a green spotted puffer (also a brackish fish that moves to marine as adults, that I acclimated the same way). My G. tile was a mere 6-7" long when I obtained him at the end of 2009, and now he measures over 15" in length, 1 1/2" thick, and is still growing with a ravenous appetite. It has been my experience that while these animals can be kept in freshwater as small babies for a short period of time, they need saltwater to thrive and succeed best in full marine conditions.

A: Excellent info. I'll add it to my moray page. Thanks. LA

LA
Hard to photograph in a flower pot in a tank.

LA
Easier outside the tank.

LA
And outside the pot.