''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 "unisp ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 ...

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 (taxonomy), family of marine ray-finned fishes, notothenioids belonging to the Perciform suborder Notothenioidei. The family comprises four genera. These fishes are endemic to deep ...

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 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the seco ...

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, 35,800 species of fish had been described as of March 2 ...

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

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 ...

and in

McMurdo Sound The McMurdo Sound is a sound in Antarctica, known as the southernmost passable body of water in the world, located approximately from the South Pole. Captain James Clark Ross discovered the sound in February 1841 and named it after Lieutenant ...

. 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 Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honours

Edward Ratcliffe Garth Russell Evans Admiral Edward Ratcliffe Garth Russell Evans, 1st Baron Mountevans, (28 October 1880 – 20 August 1957) was a Royal Navy officer and Antarctic explorer.H. G. Thursfield, 'Evans, Edward Ratcliffe Garth Russell, first Baron Mountevans (188 ...

the

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

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 epithelia ...

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 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 ...

while the

anal 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 o ...

has 28-33. This species attains a maximum

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

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 List of Antarctic and sub-Antarctic islands, 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 List of Antarctic and subantarctic islands, Antarctic islands located in the Drake Passage with a total area of . They lie about north of the Antarctic Peninsula, and between southwest of the n ...

, the northern tip of

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. ...

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 islan ...

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 m ...

and benthic

crustaceans Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of Arthropod, arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquat ...

References

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