Freshwater/Brackish Eel and appropriate tank setup questions

[bubo]

My fiancee is utterly fascinated by aquarium eels. I've decided that I am going to plan a surprise for her and setup an aquarium with an eel for her enjoyment. This will be our second aquarium, and the third that I have setup and managed. I don't think that I am ready to handle the challenge of a large saltwater tank, but I see freshwater and brackish eels at many of the lfs that I frequent. However, it seems like everywhere that I read, I find that people are complaining about being mislead about freshwater and brackish eels. This makes me really suspicious of the information provided by commercial sources, and I seem to have trouble finding websites with eel care information that are not trying to sell me the fish/products.

I have two questions right now. First of all, which eels are happy in brackish water (I'd prefer fresh water, but I'm under the impression that all "freshwater" eels are both young and mislabelled). I would be happy to also know of non-eels that are both eel-like, active and of similar size to an eel (I know true eels are secretive, but if I do end up with only an eel-like fish instead of a true eel, I'd like for it to be a little more active).

My second, and more important question, is some guidance in setting up a new aquarium that will allow the eel to be happy. While I know that the tank is going to have to be fairly long, I can only find suggestions about substrate and feeding through answers to other questions, and it has left me a little confused. I do know that the water quality is going to depend on the type of eel I select. I would also like to know if there is any kind of structure/decoration that will make the eel happier (besides the cave/tunnel for it to hide in), and what precautions I need to take to protect the eel (I've seen one reference to them being escape artists, but it was just a vague warning to secure the top of the tank).

I would also like to know if there is any additional equipment (besides a hydrometer) for keeping a brackish tank instead of a freshwater tank.

 

[BrianNY]

You've asked some great questions and I love the topic. Many people (including myself), are fascinated by eels. Before I respond, I'd like to know how many gallons you are going to have available for your fiancees pet?

 

[fishstixs05]

For a long time kept a freshwater moray eel http://www.theaquarians.net/ArticlesandWallpapers/morayarticle.htm
in a 20 gallon aquarium, and he was very happy in there. The one problem is that I would rarely see him, but he way very cool. One way to keep one is the take pvc pipe and fix several t-pipes connected that pop up for the eel to swim through (if this isnt clear tell me and i will try to explain better). Then, add gravel over(dont get it in the pipes, and rocks around. You end up with a natural looking aquarium with underground tunnels. "What good does this do, it gives him a place to hide" you might be thinking, but the eels will feels more secure with the tunnels, and therefore will come out more knowing he has a hole to dive in if he is threatened. Food i fed him were shrimp i put down on a skewer. Another alternative are dojo loaches. They can get up to a foot long and have a somewhat eel like appearance.
http://www.loaches.com/species_pages/wloach.html

 

[Menagerie]

I would also like to know if there is any additional equipment (besides a hydrometer) for keeping a brackish tank instead of a freshwater tank.

Marine salt, but you won't need a ton of it!

 

[bubo]

BrianNY: I'm looking to put this tank together around either Christmas time, or next April depending on the costs of getting the tank setup correctly. I've been looking at dimensions instead of gallons because of some posts I saw that said an eel tank should be "as long as at least twice the maximum length of the eel" but that width was not as critical. My early estimation is 70 gallon minimum, but that won't be set in stone until I select the eel. I'm still investigating tank companions, since most eels (I think) will end up seeing tank mates as food. I'm also debating on raising live food in the tank with the eel, or setting up a seperate tank for them. I'd have to investigate whether the eel I select will over eat when given the chance. Regardless, I intend to have more than enough gallons to keep our eel and friends happy.

fishstixs: I've actually seen that tunnel system described before. I've seen dojo loaches and like them myself, but I didn't know that they grew to a foot in length. 8O At the time, I decided not to get them because I have apple snails that I adore, and now that I know what size they grow to I'm glad that I didn't get them. I would need to buy a new tank much earlier! Thank you for the information!

 

[BrianNY]

Gotchya bubo. The coolest tank I've ever seen (in anyones home), was basically an eel tank. Some of you NYers know the owner as Charlie (the plant guy from the GCAS).

Anyway it's a 240 gallon planted tank (Dutch Style). There's a pile of driftwood in the center of the tank, stacked to form a see through living area for the tanks main inhabitant, a huge fire eel. One of the coolest things is that the tank is also loaded with schooling tetras and barbs. I was in awe that such a huge eel wouldn't prey on these little fish. Charlie told me that the eel only eats when he hand feeds it (but admitted he could never keep count of all the school fish). *LOL*

Watching the eel slither and meander through the driftwood in the midst of all those small fish was the coolest thing.

Please let us know what species of eel you decide on.

 

[Lance M.]

For things that look kinda like eels, the dojo loach is a good one. I really like mine. He's a spotted dojo about 7 inches long right now. Very cool. I also have four trapdoor snails in my tank and he doesn't bother them at all, so I don't think they would bother apple snails but maybe it depends on the exact fish. Coolie Loaches also look similiar to eels, but don't grow nearly as long eels. Coolies can get four inches and they look like worms. Good luck with the eel tank. I've wanted to get one but I don't have room for a big tank and there are so many types of spiny eels, it gets confusing sometimes.

 

[bubo]

Lance: Dojo/Weather Loaches seem to have a hit or miss approach when it comes to snails. From the anecdotes that I've read on them, they seem to ignore snails until they happen to come across their first one while hungry. Since I've read about Dojo Loaches cleaning dead scales and parasites off of tank mates, I'm assuming that they start off doing the same thing to a snail. While doing so, they discover that the "trap door" of the shell can be pulled open and the poor snail is a tasty snack. Once a loach figures this out for the first time, they begin to prey on the snails in a tank whenever they become peckish. I've read about one that dragged a snail out of it's shell and "shook it like a dog shakes a toy" before eating it.

Decided to share a link that I found. Buried in about.com I managed to find a short species guide listing eels that can survive in brackish water, and a few that can be successfully acclimated to freshwater. The data for the list was pulled from fishbase.org It even indicates the preferred water type for the eels listed, and shows that the Spotted Freshwater Moray (Gymnothorax Polyurandon) actually prefers freshwater.

http://saltaquarium.about.com/cs/eelprofilesindex/l/blfweels.htm

While I think the Slender Giant Moray would be a really interesting brackish eel to keep, they grow to 13 feet in length and would require a minimum tank length of 26 feet to keep them happy! 8O I'm debating between the Freshwater Moray and the Spotted Freshwater Moray right now. While the Spotted looks prettier and would give me more freshwater tank mates to choose from, I've found more success stories about the plain Freshwater Moray. I'm probably going to go for the plain Freshwater Moray as a first eel, and if we have success with him we can look into a Spotted for a separate tank.

I do have a new question. Where should I go to find the actual salinity value that fish prefer? I know that brackish means slightly salty, as found when rivers empty into a salt body, but where does Brackish end and Marine begin in the amount of salt in the water? More importantly, where do I go to find out the amount of salt I should add to the water to keep an eel happy, and to determine what tank mates would be happy in that amount of salt?

 

[Toirtis]

All commonly sold 'freshwater' morays, with the exception of G.tile, are brackish, but all spiney eels (like peacocks, fire eels, etc.) are freshwater.