Channichthyidae is a family of fishes of the order Perciformes. Fish with naked body, flattened, elongated snout. There are 2-3 lateral lines. Blood is colorless (no red blood cells). Hemoglobin is absent, oxygen is carried by blood plasma. Includes 11 genera, over 15 species. Marine fishes. Inhabit the Antarctic, sub-Antarctic and temperate latitudes of the Southern Hemisphere. Bottom fishes, live at depths of 200-700 m, are found in the coastal zone. They feed on crustaceans and fish. Many Channichthyidae are of commercial importance.
Body elongate, devoid of scales, covered with well-developed layer of mucus. Head more or less compressed dorsoventrally with noticeably elongated, flattened dorsoventrally paddle-shaped snout and a very large, not extending mouth. The teeth on the jaws are small conical, arranged in several rows. The upper part of the cap bone usually has well-developed simple or branching spines. Pectoral fins are large, fan-shaped, with 18-27 rays. The pelvic fins are southerly or southerly-thoracic, broad or elongate. Two, as a rule, clearly separated by interdorsal space dorsal fins: the first fin is relatively short, with 3-15 soft barbs, in the second dorsal fin 26-47 soft articulate rays. The anal fin has 24-49 rays. The caudal fin is truncated or rounded, occasionally weakly emarginate, has 11-12 main rays. Two or three lateral lines with bony segments or rounded bony plates and free neuromasts. Gill stamens lamellate osseous or rudimentary smooth. The total number of vertebrae is 49-71, including 22-31 trunk vertebrae and 25-43 caudal vertebrae.
Blood is essentially colorless or slightly yellowish plasma, as it contains almost no formational elements - mature forms of erythrocytes and hemoglobin, and muscles usually lack myoglobin or contain it in extremely small amounts. Most species live in extremely cold conditions of high-latitude Antarctica on the verge of freezing water (up to -1.9 °C). The main gas exchange is carried out not through the gills, but through the extremely vascularized skin of the thoracic region of the body and the epithelium of the oral cavity (up to 75%). Predominantly bottom solitary species, some species can form large aggregations and partially lead a pelagic lifestyle (Champsocephalus gunnari). Juveniles are pelagic. Coastal and deep-water species inhabiting depths from a few meters to 2000 m (Chionobathyscus dewitti), mainly in high-latitude Antarctica. One species (Champsocephalus esox) inhabits the temperate waters of the Falklands-Patagonian shelf of South America. Predators and zooplanktophagous. Total length 25-75 cm.
Some species (e.g., Champsocephalus gunnari, known commercially as "icefish") are commercially important, have good flavor, tender light-colored meat, and are used in cooking.