Nototheniidae (cod icefish; subclass Actinopterygii, order Perciformes) A small family of marine fish, most species of which have an elongate body, a large head, a short first dorsal fin; the second dorsal and anal fins are long. Nototheniidae form the most numerous group of Antarctic fish, adapted to a life in extremely cold sea water. In some species the blood lacks red blood cells. Notothenia coriiceps (60 cm) feeds on a variety of bottom-dwelling invertebrates. Pleurogramma antarcticus (20 cm) is a pelagic species, dominant among Antarctic mid-water fish. There are about 59 species, found in coastal Antarctica and S. America.