''Chionobathyscus dewitti'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

belonging to the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

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

, the

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

es. This species is found in 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 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-small ...

Taxonomy

''Chionobathyscus'' was first described as a genus in 1978 by the ichthyologists

Anatoly Petrovich Andriyashev Anatoly Petrovich Andriyashev (; 19 August 1910 – 4 January 2009) was a Soviet and Russian ichthyologist, marine biologist, and zoogeographist, notable for his studies of marine fauna of the Arctic and the Northern Pacific. Notable dates * ...

and

Alexei Vladimovich Neyelov Alexey, Alexei, Alexie, Aleksei, or Aleksey (russian: Алексе́й ; bg, Алексей ) is a Russian and Bulgarian male first name deriving from the Greek ''Aléxios'' (), meaning "Defender", and thus of the same origin as the Latin A ...

when they were describing the only species in this genus ''Chionobathyscus dewitti'', the type of which had been collected in the Eastern Antarctic Ocean at 67°31'S, 33°05'W. The genus name is a compound of ''chionos'' which means "snow", although in this case this is alluding to the relationship of this taxon with the genus ''

Chionodraco ''Chionodraco'' is a genus of marine ray-finned fish belonging to the family Channichthyidae, the crocodile icefishes. They are found in the Southern Ocean. Taxonomy ''Chionodraco'' was first described as a genus in 1905 by the Swedish zoologist ...

'', and ''bathyscus'' which means "inhabitant of the deep", a reference to the depths at which this species is found. The specific name honours the American ichthyologist,

marine biologist Marine biology is the scientific study of the biology of marine life, organisms in the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifi ...

and

oceanographer Oceanography (), also known as oceanology and ocean science, is the scientific study of the oceans. It is an Earth science, which covers a wide range of topics, including ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamic ...

Hugh Hamilton DeWitt in recognition of his work on Antarctic fishes.

Description

''Chionobathyscus dewitti'' has a vestigial spine on the snout, really just a small knob. There are 3 or 4 branched spines on the operculum. There are 3 lateral lines which do not have bony plates. The pelvic fin is elongated and has thickened skin at their tips. The first and second

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

s are clearly separated. Within the dorsal fin there are 5 or 6 spines and 39 or 40 soft rays while the anal fin has 33 or 34 soft rays. They are an overall gray colour, paler centrally, with juveniles being a lighter colour than adults. There body is marked with 5 wide bars and the fins are pale except for the rear parts of the

pectoral Pectoral may refer to: * The chest region and anything relating to it. * Pectoral cross, a cross worn on the chest * a decorative, usually jeweled version of a gorget * Pectoral (Ancient Egypt), a type of jewelry worn in ancient Egypt * Pectorali ...

and

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s. This species attains a maximum total length of .

Distribution, habitat and biology

Chionobathyscus dewitti is found in the Southern Ocean and is probably circum-Antarctic on the continental shelf and slope. It is a bathydemersal species with a depth range of . The adults feed largely on fishes

krill Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian word ', meaning "small fry of fish", which is also often attributed to species of fish. Krill are consi ...

. They have been caught in prespawning condition in February.

References

{{Taxonbar, from=Q13470020 Channichthyidae Monotypic fish genera Fish described in 1978 Taxa named by Anatoly Andriyashev Fish of the Southern Ocean