Any of more than 800 species of carnivorous fishes (suborder Gobioidei, order Perciformes), found worldwide but especially abundant in the tropics.
Most species are small bottom dwellers with a weak suction cup formed by the fusion of their pelvic fins. About 700 species are typically elongated, sometimes scaleless fishes found along shores and among reefs in tropical and temperate seas. They have two dorsal fins and a rounded tail, lack a lateral line (sensory organ along the side of the body), and are often brightly coloured. Most adults are no longer than 4 in. (10 cm).