''Vomeridens'' 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 ''Vomeridens infuscipinnis''. 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

''Vomeridens'' was first described as a genus in 1980 by the

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 ...

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

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 ...

with its only species having been described by DeWitt as ''Racovitzia infuscipinnis'' in 1964. The type locality of ''R. infuscipinnis'' was given as the

Weddell Sea The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha ...

. Its genus name ''vomeridens'' is a reference to the teeth on the vomer while the specific name ''infuscipinnis'' is a compound of ''infuscus'' meaning "dark brown" and "pinnis" which means "finned", a reference to the colour of the

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 se ...

Description

''Vomeridens'' has a 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 with two lateral lines consisting of tubular scales. The operculum has no spines or hooks. The jaws have bands of small conical teeth. There are no teeth on the

palatines Palatines (german: Pfälzer), also known as the Palatine Dutch, are the people and princes of Palatinates ( Holy Roman principalities) of the Holy Roman Empire. The Palatine diaspora includes the Pennsylvania Dutch and New York Dutch. In 1709 ...

but specimens with a

standard 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 m ...

greater than typically have teeth on the

vomer The vomer (; lat, vomer, lit=ploughshare) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxill ...

. There are 31-34 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 31-32. This species attains a maximum standard length of . In alcohol, the body and head are brown darker on the abdomen. The

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

s are dusky, the

is dark while the other fins are light coloured.

Distribution, habitat and biology

''Vomeridens'' is found in the Southern Ocean where it is known to occur in the Weddell and

Ross Ross or ROSS may refer to: People * Clan Ross, a Highland Scottish clan * Ross (name), including a list of people with the surname or given name Ross, as well as the meaning * Earl of Ross, a peerage of Scotland Places * RoSS, the Republic of Sou ...

seas, 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 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 ...

. It is a

bathydemersal Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They occ ...

species occurring at depth between . It is a rare species. They have a reduced amount of bone and a high percentage of cartilage and lipids in their bodies which gives them near neutral buoyancy. This reduced body density means that this species probably forages in the water column, hovering over the substrate. Sampled stomach contents were wholly made up of

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 Norwegian, Norwayan, or Norsk may refer to: *Something of, from, or related to Norway, a country in n ...

(''Euphausia superba''), with some of these being in length. Seven females sampled had a fecundity of 1576 to 2296 ova.

References

Bathydraconidae Monotypic fish genera Taxa named by H. H. DeWitt Fish described in 1964 Fish of Antarctica {{Bathydraconidae-stub