; subclass Actinopterygii, order Perciformes)
A large family of small fish found in marine, brackish, and freshwater environments. Like the related gobies, they have a fairly round body, a blunt head with the eyes located almost above the jaws, two dorsal fins, and a rounded tail fin. Unlike gobies, the ventral fins of the gudgeons are close to one another but do not form a sucking disc. One of the largest species is Gobiomorus dormitor (bigmouth sleeper) which grows to 60 cm; most do not exceed 20 cm. There are about 150 species, distributed world-wide.
Subjects: Zoology and Animal Sciences.