''Racovitzia'' is a

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. 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 ...

around

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 contine ...

Taxonomy

''Racovitzia'' was formally described as a genus in 1900 by the Belgian

palaeontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Louis Dollo Louis Antoine Marie Joseph Dollo (Lille, 7 December 1857 – Brussels, 19 April 1931) was a Belgian palaeontologist, known for his work on dinosaurs. He also posited that evolution is not reversible, known as Dollo's law. Together with the Austrian ...

when he was describing the only species in what was then considered to be 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, ''Racovitzia glacialis'' the type of which had been collected by the

Belgian Antarctic Expedition The Belgian Antarctic Expedition of 1897–1899 was the first expedition to winter in the Antarctic region. Led by Adrien de Gerlache de Gomery aboard the RV ''Belgica'', it was the first Belgian Antarctic expedition and is considered the firs ...

off the Antarctic at 71°23'S, 87°32'W or 71°19'S, 87°37'W. In 1916 Edgar Ravenswood Waite described ''Aconichthys harrisoni'' which has since been determined to be the second species in the genus, however some authorities consider that ''R harrisoni'' is a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

of ''R. glacialis''. The genus name honours the Romanian

biologist A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual Cell (biology), cell, a multicellular organism, or a Community (ecology), community of Biological inter ...

Emil Racoviță Emil Gheorghe Racoviță (; 15 November 1868 – 19 November 1947) was a Romanian biologist, zoologist, speleologist, and Antarctic explorer. Together with Grigore Antipa, he was one of the most noted promoters of natural sciences in Romani ...

who was the naturalist aboard the ''

Belgica Gallia Belgica ("Belgic Gaul") was a Roman province, province of the Roman Empire located in the north-eastern part of Roman Gaul, in what is today primarily northern France, Belgium, and Luxembourg, along with parts of the Netherlands and German ...

'' the ship which carried and supported the

Species

There are currently two recognized species in this genus: * '' Racovitzia glacialis'' Dollo, 1900 * '' Racovitzia harrissoni'' ( Waite, 1916)

Characteristics

''Racovitzia'' has a slender elongated body which is only slightly compressed and has a long spatulate snout. The body is covered with small,

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. There are three

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 which are made up of tubular scales. There is a strong ridge on the operculum which ends either in a rounded point or a small number of serrations. The jaws have band of small conical teeth. ''R. glacialis'' 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 .

Distribution habitat and biology

''Racovitzia'' are found in the Southern Ocean with ''R. glacialis'' having a circum-Antarctic distribution on 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 ...

as well as around the

South Sandwich Islands ) , anthem = "God Save the King" , song_type = , song = , image_map = South Georgia and the South Sandwich Islands in United Kingdom.svg , map_caption = Location of South Georgia and the South Sandwich Islands in the southern Atlantic Oce ...

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 Elephant Island Elephant Island is an ice-covered, mountainous island off the coast of Antarctica in the outer reaches of the South Shetland Islands, in the Southern Ocean. The island is situated north-northeast of the tip of the Antarctic Peninsula, west-so ...

and

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 ...

. ''R. harrissoni'' is restricted to the southeastern Pacific Ocean off Chile. They are

demersal The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...

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 ...

, deep water fishes found down to around . Their biology is little known but they have been recorded feeding on

amphipods Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descri ...

and

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 ...

, and they are probably largely dependant on krill. The presence of larvae in late November suggests that the eggs hatch in Spring.

References

{{Taxonbar, from=Q2199781 Bathydraconidae Fish of Antarctica Taxa named by Louis Dollo