Pic? If you can get a decent picture of him ideally with a halfway decent showing of it's sides and belly we can give you a positive ID. I'm guessing it's one of 3 species... expect min size to be 18" for any of these. Armatus, Favrus, of Dayii are teh 3 commonly mislabeled as zig zags... the first 2 liekly being the fish you have. If it has an unpatterned belly it's likely Armatus or less likely Dayii... THe first getting up to 30" full grown.. the second getting approx 18" .. Favrus will have an unbroken pattern extending under it's belly and get 18"+ but unlikely larger then 24"
Expect any of these fish to get 18"+ within' 1-2yrs. imo a 75 is min for any of them during this time with few tank-mates. I would give an Armatus the same tank needs as a Fire eel long-term, imo ideally something in the 300+ gallon range.
Also a warning I've had Armatus, and Dayii that ate small fish, these fish imo are more semi-aggressive then comm fish and often suitable tank-mates for the more docile cichlid species. Anything that can fit in their mouthes ( larger then they appear) are fair game to these predetors.
Now that I've scared you... imo these are one of the most rewarding fish to keep in the hobby, and worth every headache. They tame infinatly more then an Oscar and ime are far more intelligent. They are a true wet pet if you want something that interacts with it's owner, they are amazing fish to own.
