Note: Do not rely on this information. It is very old.
Fighting Fish
Fighting Fish, the translation of the Siamese name of Betta pnquax, a small fish of the Acanthopterygian family Labyrinthici. An artificial variety of it is reared for fighting in Siam, where encounters between these fish are a favourite amusement. When the fish is quiet it is dull-coloured, but if it sees an antagonist or its own image in a looking-glass, "the whole body shines with metallic colours of dazzling brilliancy, while the projected gill-membrane, waving like a black frill round the throat, adds something of grotesqueness to its appearance." In this state it makes repeated darts at its real or reflected antagonist.