blenny, common name of various species of extremely numerous small fishes belonging to the suborders Blennioidei (blennies) and Notothenioidei (Antarctic blennies). They are characterized by elongated, tapering bodies and a continuous long dorsal fin. Blennies live on the sea bottom, among reefs, rocks, or kelp, in burrows or shells, or among eelgrass or algae in shallow brackish water; some species are found in freshwater. A number of species spend long periods out of water in moist tidal zones. They feed on small invertebrates. Some blennies have scales and some do not; certain species have fleshy filaments on the head. Tropical Atlantic species include the striped blenny (found as far north as New York) and the more southerly freckled blenny. Those that live in kelp beds are mottled in coloration and those found in eelgrass are silver and green, matching their environment. The closely related wolffishes of the family Anarhichadidae, with large, tusklike teeth, are found in arctic Atlantic waters. They average 3 ft (90 cm) in length and are good food fishes, sold commercially as "ocean catfish." Blennies are classified in the phylum Chordata, subphylum Vertebrata, class Osteichthyes, order Perciformes, suborders Blennioidei and Notothenioidei.