Ogilby's ghostshark (''Chimaera ogilbyi''), also known as the whitefish, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

chimaera Chimaeras are cartilaginous fish in the order Chimaeriformes , known informally as ghost sharks, rat fish, spookfish, or rabbit fish; the last three names are not to be confused with rattails, Opisthoproctidae, or Siganidae, respectively. At ...

, native to the waters of

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and southern

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. It lives near the ocean floor 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 ...

and

continental slope A continental margin is the outer edge of continental crust abutting oceanic crust under coastal waters. It is one of the three major zones of the ocean floor, the other two being deep-ocean basins and mid-ocean ridges. The continental margin ...

deep. It reaches a maximum size of . Reproduction is

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

and eggs are encased in horny shells. It reaches maturity between in length. It is listed as a

near-threatened species A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(IUCN) due to steep declines in population in areas affected by trawling. Ogilby's ghostshark was formerly placed in the genus ''

Hydrolagus ''Hydrolagus'' is a genus of fish in the family Chimaeridae found in the Atlantic, Indian and Pacific Oceans.Weigmann, S. (2016)Annotated checklist of the living sharks, batoids and chimaeras (Chondrichthyes) of the world, with a focus on biogeog ...

'' based on its appearance, but a 2018 genetic study of

mitochondrial A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is use ...

DNA markers found that it was nested within the genus ''

Chimaera Chimaeras are cartilaginous fish in the order Chimaeriformes , known informally as ghost sharks, rat fish, spookfish, or rabbit fish; the last three names are not to be confused with rattails, Opisthoproctidae, or Siganidae, respectively. At ...

''. Alongside ''H. ogilbyi'', three other putative ''Hydrolagus'' populations defined by mitochondrial DNA were found to nest within ''Chimaera'': ''Hydrolagus lemures'' (from

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

), and two unnamed populations from southern Indonesia and northern

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

. These four populations are indistinguishable from each other according to

nuclear DNA Nuclear DNA (nDNA), or nuclear deoxyribonucleic acid, is the DNA contained within each cell nucleus of a eukaryotic organism. It encodes for the majority of the genome in eukaryotes, with mitochondrial DNA and plastid DNA coding for the rest. It ...

and morphological (appearance)-based data. As a result, the four populations were combined into one species, for which ''Chimaera ogilbyi'' is the oldest name. Specimens formerly placed in the species ''Hydrolagus lemures'' (the bight ghostshark or blackfin ghostshark) are found in the waters of

from

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

where, near the ocean floor of the

and upper slope. Their depth range is between from the surface. They reach 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 .

References

External links

* *

Ogilby's ghostshark Ogilby's ghostshark (''Chimaera ogilbyi''), also known as the whitefish, is a species of chimaera, native to the waters of Australia and southern Indonesia. It lives near the ocean floor on the continental shelf and continental slope deep. It ...

Marine fish of Australia Fish of Indonesia

Taxonomy articles created by Polbot {{Chondrichthyes-stub