''Prionodraco'' 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 "unispec ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 hor ...

belonging to the

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

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 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 Antarcti ...

es, its only species is ''Prionodraco evansii''. These fishes 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 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-small ...

Taxonomy

''Prionodraco'' was first described as a genus in 1914 by the British

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, 33,400 species of fish had been described as of Octobe ...

Charles Tate Regan Charles Tate Regan FRS (1 February 1878 – 12 January 1943) was a British ichthyologist, working mainly around the beginning of the 20th century. He did extensive work on fish classification schemes. Born in Sherborne, Dorset, he was educat ...

when he was describing the only species in this

genus ''Prionodraco evansii'', the type of which had been collected by the ''Terra Nova'' Expedition in 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 vi ...

and in

McMurdo Sound McMurdo Sound is a sound in Antarctica. It is the southernmost navigable body of water in the world, and is about from the South Pole. Captain James Clark Ross discovered the sound in February 1841, and named it after Lt. Archibald McMurdo o ...

. The genus name compounds ''prion'' which means "saw", a reference to V-shaped serrated bony plates on the flanks and ''draco'' meaning "dragon", a common suffix used in name notothenioids, while the specific name honours Edward Ratcliffe Garth Russell Evans the

captain Captain is a title, an appellative for the commanding officer of a military unit; the supreme leader of a navy ship, merchant ship, aeroplane, spacecraft, or other vessel; or the commander of a port, fire or police department, election precinct, e ...

of the '' Terra Nova''.

Description

''Prionodraco'' has a scaleless naked body with a quadrilateral cross-section which has scales only on the lateral lines and bony V-shaped plates with serrated margins situated along the angles of the body. There are 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 epithelial ...

s, the middle line only having perforated scales while the upper one has tubed scales. The jaws are lined with bands of small conical teeth, some of which may be enlarged. The ridge on the operculum ends in a hooked spine. There are 34-38 soft rays in 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 conv ...

while the

anal 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 se ...

has 28-33. This species attains a maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of and a maximum published weight of . In alcohol, the overall colour is brown with variably sized black spots on the head and body and a large dark spot on the

Distribution and habitat

''Prionodraco'' occurs in the Southern Ocean and has been recorded from the

South Orkney Islands The South Orkney Islands are a group of islands in the Southern Ocean, about north-east of the tip of the Antarctic Peninsula South Shetland Islands The South Shetland Islands are a group of Antarctic islands with a total area of . They lie about north of the Antarctic Peninsula, and between southwest of the nearest point of the South Orkney Islands. By the Antarctic Treaty of 195 ...

, the northern tip of

Antarctic Peninsula The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martín 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 Antarctic ...

as far south as 65°S and the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

of Antarctica. They are demersal fishes which are found at depths of .

Biology

''Prionodraco'' spawning appears to take place in the autumn and early winter. The eggs probably hatch in the following spring and the total length of the larvae at hatching is around , the pelagic phase of the larvae is brief. Sexual maturity is reached at a total length of . Their diet is dominated by

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are mad ...

and benthic

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

References

{{Taxonbar, from=Q2005854 Bathydraconidae Monotypic fish genera Fish of Antarctica Fish described in 1914 Taxa named by Charles Tate Regan