I had peacock gudgeons a few years ago. They are quite peaceful fish, except if there are 2 males in a smallish space like a 20 high. I would get 1 male and 2 or 3 females. Learn how to tell the difference before going shopping. Mature males have a hump on their heads but the fish in shops are immature so their heads all look female. The thing to look at is the anal fin. Females have a dark edge to the fin, it doesn't have to be the whole length even a small bit shows it's a female. Males do bot have any dark colour on the edge of the fin.
