I hope it's not would like him to stay small I like him

I don't think it's a look down from the pics I've seen of juveniles they are more camouflaged like weeds.


http://www.thejump.net/id/lookdown.htm

I think it's a juvenile file fish of some kind of it's not a common one like a matted, but a more uncommon species. I would call the lfs and ask. (mostly because I'm curious as well lol)
Either way a very cool looking fish hope it works out.