This is by far one of the more interesting species which is made commonly available to interested aquarium hobbyists (I must admit, I AM partial to eels). For those of us who prefer a bit more flare to our tank community without the aggression or extensive care required by other exotic species, the peacock/tiretrack/spiny eel is an excellent addition to the aquatic environment. As was aforementioned, their inclination to burrow may either be supported by providing a finer substrate for them to enjoy (and they will!), or suppressed by installing several rock caves and foliage for shelter. I personally prefer the latter, as it is not only more aesthetic for you, but if cleverly arranged (utilizing the mirror-reflective glass tank sides) it may allow you to observe this shy fish without his being aware of your snoopish intrusion. They are indeed excellent escape artists, even when the water level is kept below the top, though this is certainly a deterrent if not fool-proof. I am in favor of Bowsie's recommendation of plastic mesh as opposed to my sloppy and, as it turns out, sadly inadequate attempt with cardboard and duct tape. If you truly adore your eel, make sure your anti-escape apparati are thorough and secure! I discovered that my eel was particularly fond of live blackworms (sewer-worms), and contrary to the opinions of many others I encountered no adverse affects of feeding this "dirty" food source to him or any other fish I have kept. He also readily consumed frozen brine shrimp, shrimp pellets, and virtually any other sustenance which found its way to his territory. I never experienced any aggression with my eel, though I have read in more than one book that they have definite potential for it. Regardless, I would whole-heartedly recommend this species to any interested hobbyist, so long as they have sufficient space to harbor it.
I myself have two eels (both in the same tank), one is a 12 cm fire eel and the other is an 18 cm tire track eel. I had had my tire track eel for about 6 months before I bought the fire eel, which meant it was already settled in and so, on introduction of its new tank mate, he decided to become a bully and nip at the fire eel's tail at every opportunity. He did this to the extent that the fire eel lost small patches of skin and caught white spot (ichthyopthirius), but after a few days of feeding the tire track eel on large earthworms, and treating the fire eel for the white spot, they settled down and do not bother each other anymore. This is the only time I have seen any aggressive behaviour from either eel. They are provided with fine gravel, but only the tire track eel buries itself while the other just likes to hide around a ceramic plant pot, which I had initially placed in the tack for my bristle nose catfish (Ancistrus dolichopterus). My eels will not eat anything that does not move, so they get live bloodworms and earthworms (it is illegal to use feeder fish here in the UK and my eels don't seem to have any inclination to eat live fish, for I have a pair of small tiger barbs which are ignored by the eels). As of yet I have not found either eel to be much of an escape artist, as my tank has a few openings large enough for these eels to escape out of and I would not say that the water level is kept lower than it would otherwise be kept at either. For at this moment I have a 10 litre plastic tank with a screened lid, modified to accommodate an internal box filter and thermostat. I implemented this modification using the section of the lid designed to accommodate an incandescent red heat lamp housing, if the tank is used to house reptiles. I am getting them a 30 litre tank soon, before moving them to a much larger tank this fall. Being 17 (and a college freshman) I do not get very long to care for my fish. In this respect, I find eels to be easy to keep and I recommend them to all hobbyists, no matter how experienced.
I have had a 20 cm Tire Track Eel for about 3 months now. I didn't see him for the first month until I started feeding him freezed dried shrimp. He loves it. I have also arranged my tank with caves and plants so he can slither around and keep somewhat covered. I see him all through the day now. He also eats ghost shrimp, fresh shrimp (from the grocery) and feeder ruby reds. I have angels, discus, puffers and parrots along with a few bottom feeders and they all get along great. But if he doesn't get shrimp for a few days, he will take a nice v-shaped chunk out of one of the angels tails. He will also chase anyone who has a shrimp hanging out of their month and steal all or part of the shrimp if he can catch them. He very rarely goes to the top of the tank, only if there's a shrimp floating and then he grabs it and heads right back to the bottom. He is my favorite in the tank, simply because he is so fascinating to watch as he becomes more outgoing.
I know this is going to sound a bit crazy after reading the other eel comments, but I've had my eel in a completely uncovered 75 liter tank for most of a year now without any problems. I have a vertical fake driftwood piece that he lives in, with an opening that is about 3 cm below the surface of the water. I frequently see him poking his head out during the day, keeping up with what's going on, and most nights if I turn the room light on after dark, I'll find him lurking around the bottom of the tank, looking for guppies, rosy reds, or ghost shrimp. He shares the tank with some gouramis, tiger barbs and others. He is now about 20 cm long. I don't know why he's content in the tank, when everyone else seems to have trouble keeping theirs in covered tanks, but (knock wood) so far there's been no problem.
I've had a tiretrack eel for about a year now. He was 8 cm when I got him and started feeding him live bloodworms and ghost shrimp. He's now 50 cm at least. He was started off in my 75 liter and was moved to my 250 liter after a few weeks, due to swimming up the filter every day even with the water down. His tank mates are 1 black ghost 25 cm, 1 irridiscent shark 20 cm, 2 twigtail cats and 10 giant danios. He now eats feeders only, and won't even turn his head for anything else. He doesn't bury himself even in the fine gravel or hides, and my light never goes off. A very beutiful fish and I would recommend him to anyone with a large enough tank because he will grow. Have fun and enjoy...
I, like John, have never had any problems with my peacock eel (who my girlfriend calls 'Snuffy' after the Sesame Street character with the equally long nose) trying to escape. I've had him for nearly two years now and, as mentioned in statements by others, has spent most of that time hiding. From talking to other people who also keep peacock eels, it seems that they do vary in temperament from complete isolationists to mildly gregarious, though mild seems to be as far as it goes on the gregariousness stakes. Have not experienced any problems with aggression either.