''Sebastes melanostictus'', the blackspotted rockfish, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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 subfamily

Sebastinae Sebastinae is a subfamily of marine fish belonging to the Family (biology), family Scorpaenidae in the Order (biology), order Scorpaeniformes. Their common names include rockfishes, rock perches, ocean perches, sea perches, thornyheads, scorpion ...

, the rockfishes, part of 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 ...

Scorpaenidae The Scorpaenidae (also known as scorpionfish) are a family (biology), family of mostly ocean, 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 ...

. It is found in the northern Pacific Ocean.

Taxonomy

Sebastes melanostictus was first formally described in 1934 as ''Sebastodes melanostictus'' by the Japanese

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, 35,800 species of fish had been described as of March 2 ...

Kiyomatsu Matsubara was a Japanese people, Japanese marine biologist, ichthyologist, and herpetologist. Born Kiyomatsu Sakamoto in Hyogo Prefecture, Kiyomatsu Matsubara was the first professor of the Department of Fisheries of the University of Kyoto and is consider ...

with the type locality given as

Kazusa Province was a province of Japan in the area of modern Chiba Prefecture. The province was located in the middle of the Bōsō Peninsula, whose name takes its first ''kanji'' from the name of Awa Province and its second from Kazusa and Shimōsa province ...

in Japan. This

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

has been considered to be a synonym of the

rougheye rockfish The rougheye rockfish (''Sebastes aleutianus'') is a rockfish of the genus ''Sebastes''. It is also known as the blackthroat rockfish, rougheye seaperch, blacktip seaperch, longlife seaperch or the blacktip rockfish and grows to a maximum of abo ...

(''S. aleutianus'') but is now accepted as a valid species and both it and the rougheye rockfish are classified within the

subgenus In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the ge ...

''Zalopyr''. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''melanostictus'' , means "black spotted".

Description

''Sebastes melanostictus'' is similar to the rougheye rockfish and both these species have eight pairs of spines on the head plus at least two infraorbital spines. The

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

has 12-14 spines and 12-15 soft rays while the

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

has 3 spines and 7 or 8 soft rays. This species is usually darker in colour than the rougheye rockfish and is farther distinguished by the presence of dark spots on the spiny part of the dorsal fin, although this is sometimes obscured by dark blotches. The overall colour of the body is pink to red marked with dark spots. Some specimens may be darker with a black or greenish tint to the overall colour with dense mottling and spots on the

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 ...

, there is a rare dusky morph which shows little mottling. There are sometimes three white spots along the base of the dorsal fin. This species attains a maximum total length of .

Distribution and habitat

''Sebastes melostictus'' is found from Japan around the northern Pacific through the

Kuril Islands The Kuril Islands or Kurile Islands are a volcanic archipelago administered as part of Sakhalin Oblast in the Russian Far East. The islands stretch approximately northeast from Hokkaido in Japan to Kamchatka Peninsula in Russia, separating the ...

Aleutian Islands The Aleutian Islands ( ; ; , "land of the Aleuts"; possibly from the Chukchi language, Chukchi ''aliat'', or "island")—also called the Aleut Islands, Aleutic Islands, or, before Alaska Purchase, 1867, the Catherine Archipelago—are a chain ...

, and north into the

Bering Sea The Bering Sea ( , ; rus, Бе́рингово мо́ре, r=Béringovo móre, p=ˈbʲerʲɪnɡəvə ˈmorʲe) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasse ...

, as far north as 60.5°, then south along the western coast of North America south to the Coronado Bank off

southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural List of regions of California, region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal reg ...

. It is a

benthopelagic 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 ...

species found at depths between , although it is typically found between . They are found close to substrates of sediments where there are many boulders and the slope is greater than 20°.

Biology

''Sebastes melanostictus'' has been treated as synonymous with ''S. aleutianus'', which has a little known biology anyway, and separate details of its biology are sparse. Like other rock fish it is predatory and crangid and pandalid shrimps are the most common prey items while larger individuals, i.e. those longer than eat a lot of fishes, other known prey are

gammarid Gammaridae is a family (biology), family of Amphipoda, amphipods. In North America they are included among the folk taxonomy, folk taxonomic category of "Scud (crustacean), scuds", and otherwise gammarids is usually used as a common name. They ...

amphipod 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 10,700 amphipod species cur ...

mysid Mysida is an order of small, shrimp-like crustaceans in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch or "marsupium" in females. The fact that the larvae are reared in thi ...

crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...

polychaete Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called c ...

s, and

octopus An octopus (: octopuses or octopodes) is a soft-bodied, eight-limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like oth ...

es. The oldest recorded individual in this species pair was 205 years old and this specimen was taken in southern Alaska. Half of the females in a stock of either species are sexually mature at 20 years old. Off

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

''S. aleutianus/S. melanosticta'' breed in April and like their

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparity, oviparous and live-bearing viviparity, viviparous reproduction. Ovoviviparous animals possess embryos that develo ...

congeners the fertilised eggs stay in the ovaries until the larvae are extruded and are given some nutrient by their mother, The larvae of ''Sebastes'' rockfishe occur near the surface where they are opportunistic feeders on invertebrate eggs,

copepod Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sedimen ...

s 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 ...

. As juveniles they are found in midwater preying on larger animals. The pelagic larvae of ''Sebastes'' rockfishes have been recorded as far as from the coast of British Columbia and there is no evidence to suggest that the larvae and juveniles of this species complex have a different life history and biology from those of most of the congeners. It is thought that predators of the fishes include

Pacific halibut The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the continen ...

(''Hippoglossus stenolepis''),

Pacific cod The Pacific cod (''Gadus macrocephalus)'' is a species of ray-finned fish in the family Gadidae. It is a bottom-dwelling fish found in the northern Pacific Ocean, mainly on the continental shelf and upper slopes, to depths of about . It can grow ...

(''Gadus macrocephalus'') and the

sablefish The sablefish (''Anoplopoma fimbria'') is one of two members of the fish family Anoplopomatidae and the only species in the genus ''Anoplopoma''. In English, common names for it include sable (US), butterfish (US), black cod (US, UK, Canada), ...

(''Amoplopoma fimbria'').

Fisheries

''Sebastes melanostictus'' inhabiots deep water where fishing effort is low and there is not thought to be a targeted fishery for this species. However, catch surveys off

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

and

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

are suggesting that this species is making up much of the rockfish catch as it lives at depths where fishing is less restricted by the existing fishing regulations.

References

External links

* * {{Taxonbar, from=Q25473247 Fish described in 1934 Taxa named by Kiyomatsu Matsubara Commercial fish Fish of the Pacific Ocean Sebastes