''Sebastes schlegelii'', also known as the Korean rockfish, northern black seaperch, black rockfish, and woo-reok (우럭) in Korean, is a

predatory Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

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 ...

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 subfamily Sebastinae, the rockfishes, part of 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 ...

Scorpaenidae The Scorpaenidae (also known as scorpionfish) are a family of mostly marine fish that includes many of the world's most venomous species. As their name suggests, scorpionfish have a type of "sting" in the form of sharp spines coated with venom ...

It is found in the Northwest Pacific Ocean.

Taxonomy

''Sebastes schlegeli '' was first formally described in 1880 by the German

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ...

and

paleontologist 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 ...

Franz Martin Hilgendorf with the type locality given as

Tokyo Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...

and

Hakodate is a city and port located in Oshima Subprefecture, Hokkaido, Japan. It is the capital city of Oshima Subprefecture. As of July 31, 2011, the city has an estimated population of 279,851 with 143,221 households, and a population density of 412.8 ...

in Japan. Some authorities place this species in the subgenus ''Acutomentum'', of which it is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

. The specific name honours the German

ornithologist Ornithology is a branch of zoology that concerns the "methodological study and consequent knowledge of birds with all that relates to them." Several aspects of ornithology differ from related disciplines, due partly to the high visibility and th ...

and herpetologist Hermann Schlegel, who, cowrote ''Fauna Japonica'' with

Coenraad Jacob Temminck Coenraad Jacob Temminck (; 31 March 1778 – 30 January 1858) was a Dutch people, Dutch Aristocracy (class), aristocrat, Zoology, zoologist and museum director. Biography Coenraad Jacob Temminck was born on 31 March 1778 in Amsterdam in the Dut ...

in which they reported this species as '' S. inermis''.

Distribution

The species is found in the Northwest Pacific Ocean, off China, the Korean Peninsula and Japan.

Description

''S. schlegelii'' are blackish with black pelvic, anal and caudal fins. The seaperch has a total of 8 weak head spines. It is black when young and turns a mottled gray on the sides with age, often nearing white. This species can vary greatly in size between bodies of water. They can live for up to 18 years, and older individuals are often much larger than average; the maximum recorded length is . The record is .

Reproduction

''S. schlegelii'' is ovoviviparous and breed via internal fertilization, females storing sperm until the development of the eggs. The phases between the start of the process and the end are separated by several months. The majority of the young are reared in late winter to early spring. Females produce between 125,000 and 1,200,000 eggs every breeding season. However it has been noted that not all of the eggs are released every year. It has been occasionally observed that the female may absorb the eggs back into her system. Along with other close related '' Sebastes'' species in the Northwest Pacific Ocean, a duplicated copy of the ''

amh AMH may refer to: Geography *''Academia Mexicana de la Historia'', the national academy of history, in Mexico *Alaska Marine Highway, ferry services along the southern coast of Alaska and to Washington state *AMH, IATA airport code for Arba Minch ...

'' gene (called ''amhy'') is the master sex-determining gene for ''S. schlegelii''. ''In vitro'' experiments demonstrate that the overexpression of ''amhy'' causes female-to-male sex reversal in ''S. schlegelii''. Further research has supported ''amhy'' as a sex marker and identified chromosome 4 as the putative sex chromosome for the species.

Ecology

It is a

pelagic fish Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that do live on or near the bottom, and reef fish that are associated with coral reef ...

, occurring 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 ...

. Like other pelagic fish, they spend most of their time amid the water columns and are generally associated with rougher terrain. Juveniles are often associated with rafts of seaweed. ''

Lepeophtheirus elegans ''Lepeophtheirus elegans'' is a species of sea lice. Known fish hosts are the stichaeids '' Chirolophis japonicus'' and '' Pholidapus dybowskii'' from Russia, Japan and Korea, the pholid '' Pholis picta'' and the cottid ''Myoxocephalus brandtii ...

'' is a species of

sea lice Sea lice (singular: sea louse) are copepods (small crustaceans) of the family Caligidae within the order Siphonostomatoida. They are marine ectoparasites (external parasites) that feed on the mucus, epidermal tissue, and blood of host fish. Th ...

reported on ''S. schlegelii''.

Fishery

They make up an important component of nearshore fisheries in northern Asia. The preference of the species for rough terrain can make it somewhat inconvenient for commercial fisheries, which are often situated in nearshore, shallow water, and rocky areas (

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

s). The species is a popular quarry for recreational anglers.

References

schlegelii Fish of Japan Fish of Russia Fish of China Taxa named by Franz Martin Hilgendorf Fish of the Pacific Ocean Fish described in 1880 {{Scorpaeniformes-stub