It's most likely a cross anyway unless you got it from a true A labiatus breeder. Is it a male? If so, it can fit in a 55g but that's too small a tank. He'll go insane and kill everything and probably turn into a glass banging maniac. Imo it's not fair to him, they need a least a 48" x 18" footprint. Putting any other fish in with him is a death sentence for one of them. my2