''Champsocephalus'' is a genus of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Channichthyidae The crocodile icefish or white-blooded fish comprise a family (biology), family (Channichthyidae) of notothenioid fishes, fish found in the Southern Ocean around Antarctica. They are the only known vertebrates to lack hemoglobin in their blood as ...

, the

crocodile icefish The crocodile icefish or white-blooded fish comprise a family (biology), family (Channichthyidae) of notothenioid fishes, fish found in the Southern Ocean around Antarctica. They are the only known vertebrates to lack hemoglobin in their blood as ...

es. They are native to the

Southern Ocean The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the world ocean, generally taken to be south of 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the seco ...

Taxonomy

''Champsocephalus'' was first formally described as a genus in 1862 by the American

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

Theodore Nicholas Gill Theodore Nicholas Gill (March 21, 1837 – September 25, 1914) was an American ichthyologist, mammalogist, malacologist, and librarian. Career Born and educated in New York City under private tutors, Gill early showed interest in natural histor ...

as he thought that its

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

, ''Chaenichthys esox'' which had been described in 1861 by

Albert Günther Albert Karl Ludwig Gotthilf Günther , also Albert Charles Lewis Gotthilf Günther (3October 18301February 1914), was a German-born British zoologist, ichthyologist, and herpetologist. Günther is ranked the second-most productive reptile tax ...

, was distinct enough to be classified in its own genus.

Species

There are currently two recognized species in this genus: * '' Champsocephalus esox'' ( Günther, 1861) (pike icefish) * '' Champsocephalus gunnari'' Lönnberg, 1905 (mackerel icefish)

Characteristics

''Champsocephalus'' species do not have a spine on the snout. There are three radiating ridges on the operculum each ending in a spine. They have two

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

s, upper and middle, and these have no bony plates. The bases of the first and second

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

s are almost continuous and the

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

emarginate The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets) ...

. The maximum

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

s of these fishes are for ''C. esox'' and for ''C. gunnari''.

Distribution and habitat

''Chamsocephalus'' icefishes are found in the Southern Ocean. They can be found off South America, the

Falkland Islands The Falkland Islands (; ), commonly referred to as The Falklands, is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and from Cape Dub ...

South Georgia South Georgia is an island in the Atlantic Ocean, South Atlantic Ocean that is part of the British Overseas Territories, British Overseas Territory of South Georgia and the South Sandwich Islands. It lies around east of the Falkland Islands. ...

, the

Antarctic Peninsula The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martin in Argentina, and originally as Graham Land in the United Kingdom and the Palmer Peninsula in the United States, is the northernmost part of mainland Antarctica. ...

Kerguelen The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the sub-Antarctic region. They are among the most isolated places on Earth, with the closest t ...

, Heard and

Bouvet Island Bouvet Island ( ; ) is an uninhabited subantarctic volcanic island and dependency of Norway. It is a protected nature reserve, and situated in the South Atlantic Ocean at the southern end of the Mid-Atlantic Ridge, it is the world's most extre ...

s. They are pelagic.

Biology

''Chamsocephalus'' icefishes are predatory and are known to feed on

krill Krill ''(Euphausiids)'' (: krill) are small and exclusively marine crustaceans of the order (biology), order Euphausiacea, found in all of the world's oceans. The name "krill" comes from the Norwegian language, Norwegian word ', meaning "small ...

, mysids and fishes.

Fisheries

''Chamsocephalus'' icefishes are fished for using trawls off South America, Kerguelen and South Georgia.

References

{{Authority control Channichthyidae Perciformes genera Marine fish genera Fish of the Southern Ocean Taxa named by Theodore Gill