''Akarotaxis'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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 ...

Bathydraconidae The Bathydraconidae, or the Antarctic dragonfishes, are a family of marine ray-finned fishes, notothenioids belonging to the Perciform suborder Notothenioidei. The family comprises four genera. These fishes are endemic to deep waters off Antarct ...

, the Antarctic dragonfish, its only species is ''Akarotaxis nudiceps''. They are 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 ...

along the continental shelf of

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...

Taxonomy

''Akarotaxis'' was first described as a genus in 1980 by the American ichthyologist

Hugh Hamilton DeWitt Hugh Hamilton DeWitt (28 December 1933-5 January 1995) was an American ichthyologist, marine biologist and oceanographer. DeWitt was born on 28 December 1933 in San Jose, California, son of Carl Bryce Seligman, a country doctor, and Honor Pettit ...

and the French ichthyologist

Jean-Claude Hureau Jean-Claude is a French masculine given name. Notable people with the name include: * Jean-Claude Ades, an Italian electronic music producer * Jean-Claude Alibert (died 2020), a French racing driver * Jean-Claude Amiot (born 1939), a French compose ...

. Its only species is ''Akarotaxis nudiceps'' which was described in 1916 as ''Bathydraco nudiceps'' by the British-born Australian

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and d ...

Edgar Ravenswood Waite with the type locality given as Queen Mary Land off the

Shackleton Ice Shelf Shackleton Ice Shelf is an extensive ice shelf fronting the coast of East Antarctica from 95° E to 105° E. It extends for an along-shore distance of about , projecting seaward about in the western portion and in the east. It occu ...

. The type was collected by the

Australasian Antarctic Expedition The Australasian Antarctic Expedition was a 1911–1914 expedition headed by Douglas Mawson that explored the largely uncharted Antarctic coast due south of Australia. Mawson had been inspired to lead his own venture by his experiences on Ernest ...

. The generic name compounds ''akaro'' meaning "short" or "small" with "taxis" which means "line" or "row", a reference to the short upper lateral line, which comprises lees than 10 tubular scales. The specific name ''nudiceps'' means "naked head", thought to be an allusion to the absence of scales on the head despite Waite not mentioning this trait.

Description

''Akarotaxis'' has a slender, body which is covered in

ctenoid A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as ...

scales and has two lateral lines, the upper lateral line having only 3-9 tubed scales in its anterior section with its posterior part being made up of poredscales which also make up the middle lateral line. The upper rear margin of the operculum has a small hook. The are equipped with small conical teeth arranged in bands. The

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 ...

has 29-33 soft rays while the anal fin has 25-28 soft rays. Specimens preserved in alcohol have a brown body with a darker head, a pale dorsal fin pale and the other fins being dusky. This species attains a maximum standard length of .

Distribution, habitat and biology

''Akarotaxis'' is found almost all around the Antarctic continent from west of the Adelaide Island to the

Ross Sea The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who ...

where it is a bathydemersal species found at depths between on the outer continental shelf and in deep troughs. It has the lowest known fecundity of the Antractic dragonfishes, laying only 2000 eggs per female.

Spawning Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquat ...

takes place from mid to late summer.

References

{{Taxonbar, from1=Q2668794, from2=Q2463468 Bathydraconidae Monotypic fish genera Fish of Antarctica Taxa named by Edgar Ravenswood Waite Taxa named by H. H. DeWitt Fish described in 1916