''Racovitzia'' is a

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

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 (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

Taxonomy

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

palaeontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

Louis Dollo 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 "unisp ...

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 fir ...

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 In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

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 Ro ...

who was the

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

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 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 epithelia ...

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, 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 .

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 islan ...

as well as around the

South Sandwich Islands The South Sandwich Islands () are a chain of uninhabited volcanic islands in the South Atlantic Ocean. They are administered as part of the British Overseas Territory of South Georgia and the South Sandwich Islands. The chain lies in the sub-A ...

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 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 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 ...

. ''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 o ...

bathydemersal Demersal fish, also known as groundfish, live and feed on or near the bottom of ocean, 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 T ...

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

amphipods Amphipoda () is an order (biology), 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 10,700 amphip ...

and

krill Krill ''(Euphausiids)'' (: krill) are small and exclusively marine crustaceans of the order (biology), order Euphausiacea, found in all of the world's oceans. The name "krill" comes from the Norwegian language, Norwegian word ', meaning "small ...

, 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