''Sebastolobus altivelis'', the longspine thornyhead, 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 ...

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 In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Sebastinae Sebastinae is a subfamily of marine fish belonging to the family Scorpaenidae in the order Scorpaeniformes. Their common names include rockfishes, rock perches, ocean perches, sea perches, thornyheads, scorpionfishes, sea ruffes and rockcods. D ...

, 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 deep waters of the northeastern

Pacific Ocean 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 definition, to Antarctica) in the south, and is bounded by the continen ...

. Longspine thornyhead are similar in appearance to shortspine thornyhead though they don't grow as large and are typically found in deeper water.

Taxonomy

''Sebastolobus altivelis'' was first formally described in 1896 by the American

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, 33,400 species of fish had been described as of Octobe ...

Charles Henry Gilbert Charles Henry Gilbert (December 5, 1859 in Rockford, Illinois – April 20, 1928 in Palo Alto, California) was a pioneer ichthyologist and Fisheries science, fishery biologist of particular significance to natural history of the western Unit ...

with the type locality given as being south of the

Alaskan Peninsula The Alaska Peninsula (also called Aleut Peninsula or Aleutian Peninsula, ale, Alasxix̂; Sugpiaq: ''Aluuwiq'', ''Al'uwiq'') is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The p ...

at Albatross station 3338 at a depth 625

fathom A fathom is a unit of length in the imperial and the U.S. customary systems equal to , used especially for measuring the depth of water. The fathom is neither an International Standard (SI) unit, nor an internationally-accepted non-SI unit. Hi ...

s. The specific name ''altivelis'' is a compound of ''altus'' which means "high" and ''velum'' meaning"sail", an allusion to the taller

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

spines than '' S. macrochir''. Longspine thornyhead rockfish

Description

''Sebastolobus altivelis'' has a moderately compressed, elongate body with a relatively large, pointed head, The spiny head is armed with strong nasal, preocular, supraocular, postocular, tympanic, parietal and nuchal spines but there are no spines on the coronal. There are spines on a ridge on the sub-orbital bone. It has large eyes which are closely set and sit on the top of the head with a depression between them. There is a single dorsal fin, clearly incised at the rear of the spiny part. There are 15–17, typically 15, strong, venomous spines and 8-9 soft rays. The third dorsal fin spine is much higher than the fourth. The

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

has 3 spines, the second spine being the longest, and 4-6 soft rays 4–6. The

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

has a square rear edge. The overall color is red to orange-red with white blotches on their back, cheeks, and the spiny part of the dorsal fin. They have dark colored gill chambers and black blotches on their flanks. This species 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 and habitat

''Sebastolobus altivelis''is native to the cold waters of the northeastern Pacific Ocean and is found from the

Aleutian Islands The Aleutian Islands (; ; ale, Unangam Tanangin,”Land of the Aleuts", possibly from Chukchi language, Chukchi ''aliat'', "island"), also called the Aleut Islands or Aleutic Islands and known before 1867 as the Catherine Archipelago, are a cha ...

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

to southern

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. Its depth range is between but it primarily occurs deeper than . It is typically found over soft substrates biu may be found at the edges of reefs on harder substrates.

Biology

''Sebastolobus altivelis'' is a solitary species which typically lies motionless on the seabed for long periods of time. This species preys on other fish and invertebrates such as amphipods and shrimp. It is a long lived species which may live for up to 45 years. Fertilization is internal and the females release the fertilized eggs in a floating, gelatinous mass in the Spring. The eggs hatch at the surface and the larvae and juveniles remain pelagic for up to 6 months. As the juveniles mature they gradually move into deeper waters although they usually remain at depths of around , in the

mesopelagic zone The mesopelagic zone (Greek μέσον, middle), also known as the middle pelagic or twilight zone, is the part of the pelagic zone that lies between the photic epipelagic and the aphotic bathypelagic zones. It is defined by light, and begins ...

. After a year the young adults they settle. Juveniles feed on

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 ...

Status

Both shortspine and longspine thornyhead have been harvested in

commercial fisheries Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often ...

with the period of peak catches occurring in the 1980s and 1990s. Separate

stock assessment Stock assessments provide fisheries managers with the information that is used in the regulation of a fish stock. Biological and fisheries data are collected in a stock assessment. A wide array of biological data may be collected for an assess ...

s for longspine thornyhead in the waters off

and the

West Coast of the United States The West Coast of the United States, also known as the Pacific Coast, Pacific states, and the western seaboard, is the coastline along which the Western United States meets the North Pacific Ocean. The term typically refers to the contiguous U.S ...

have estimated the stock as healthy (above the management limits) with

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in th ...

not occurring. In the

Canadian Canadians (french: Canadiens) are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of ...

waters off the coast of

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, a COSEWIC report declared the species a "special concern" based on the slow life history and declining trend in abundance, though no estimates of abundance or stock status were made.

References

{{Taxonbar, from=Q1235581 altivelis Taxa named by Charles Henry Gilbert Fish described in 1896