Magister armhook squid | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Order: | Oegopsida |
Family: | Gonatidae |
Genus: | Berryteuthis |
Species: | B. magister |
Binomial name | |
Berryteuthis magister | |
Subspecies | |
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Synonyms | |
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Berryteuthis magister, also known as the magister armhook squid, commander squid or schoolmaster gonate squid, is a medium-sized squid in the family Gonatidae. It is found in cold, high latitude waters of the North Pacific where it is among the most numerous squid species recorded.
There are three recognised subspecies of B. magister. The type locality of all three is Japan, although specimens have been recorded as far east as the Aleutian Islands.
The cylindrical bodies of magister armhook squid are muscular with very soft reddish brown skin. Like all gonatids, the suckers of their arms are arranged in four rows or series. But unlike other gonatids it is in females only that the suckers are modified into hooks; these hooks are on the mesial rows of the dorsal arms only. The clubs at the end of both tentacles are covered in 20 rows of suckers; these are smaller in B. magister nipponensis.
The wing-like fins at the rear of the body are rather large and may reach up to 50 percent of the mantle length. The fins are also smaller in B. magister nipponensis.
B. magister magister is known to reach a mantle length of 25 centimetres (10 in); total body length may exceed 61 centimetres (2 ft). Both B. magister nipponensis and B. magister shevtsovi are somewhat smaller, with a maximum mantle length of 17–20 centimetres (7–8 in). Females are slightly larger than males.
These squid are pelagic, roaming as deep as 1,000 metres and are associated with the continental shelf. Like other species in their family, Magister Armhook Squids are thought to undertake diel migration; by day the squid remain in the blackness of the depths. By night, they ascend to the upper layers of the water column to feed by starlight. An internal balancing organ called a statocyst ensures graceful movement.
Magister armhook squid prey upon both benthic and pelagic species; sculpins, smaller fish such as Sablefish and juvenile pollock, crustaceans including euphausiids and amphipods, and other squid. Cannibalism is also known to occur among the Magisters.
Baird's beaked whale, the short-finned pilot whale, false killer whale, Dall's porpoise and sperm whales are all known to feed upon magister armhook squid. Other predators include seabirds, northern fur seals, grenadiers, halibut and several species of salmon.
Ancistrocheirus lesueurii, the sharpear enope squid, is the only species in the genus Ancistrocheirus and family Ancistrocheiridae. With a mantle length of 25 cm (9.8 in), this moderately sized squid may be found throughout the tropical and subtropical oceans. They tend to be found at mesopelagic depths.
The Gonatidae, also known as armhook squid, are a family of moderately sized squid. The family contains about 19 species in three genera, widely distributed and plentiful in cold boreal waters of the Pacific Ocean. At least one species is known from Antarctic waters, and two from the North Atlantic. The genus Eogonatus was created for the species known as Eogonatus tinro because it did not have hooks on the tentacular club and it has 5 rows of teeth on the radula. Molecular studies in allozymes and mitochondrial DNA have indicated that this species nests within the genus Gonatus, although other authorities treat it as a synonym of Gonatopsis okutanii.
Doryteuthis plei, also known as the slender inshore squid or arrow squid, is a medium-sized squid belonging to the family Loliginidae. It occurs abundantly in coastal waters of the Atlantic Ocean, from Argentina northward to North Carolina.
Liguriella is a genus of glass squids, the genus is probably monotypic, the only species being Liguriella podophthalma. The other named species Liguriella pardus, which was described by S. Stillman Berry in 1916, is cited as a taxon inquirendum but it is suggested that there may be in fact more than one species and there are species yet to be described.
Bathothauma lyromma, the lyre cranch squid, is a highly modified species of glass squid from the family Cranchiidae with a distribution which encompasses most of the world's oceans from the tropics to high latitudes.
Sandalops melancholicus, the sandal-eyed squid or melancholy cranch squid, is a small species of glass squid. It is known to reach a mantle length of 11 cm (4.3 in). It is distributed in the tropical and subtropical oceans around the world. It is the only species in the genus Sandalops but some authorities suggest that this may be a species complex rather than a monotypic genus.
Idioteuthis cordiformis is a species of whip-lash squid found in tropical regions of the west Pacific Ocean. The species is commonly known as the 'love-heart squid' because the species name cordiformis is Latin for 'heart shaped'. Recently, this species has been found to consume small birdbeak dogfish.
Chtenopteryx sicula, also known as the comb-finned squid or toothed-fin squid, is a species of squid native to at least the Mediterranean Sea. It is characterised by several distinct morphological features: ocular photophores are present but visceral photophores are absent, arm suckers are arranged in at least 4 series distally, and club suckers are borne in more than 8 series.
Sepiola atlantica, also known as the Atlantic bobtail, is a species of bobtail squid native to the northeastern Atlantic Ocean and the Mediterranean Sea.
Gonatus onyx is in the class Cephalopoda and in the phylum Mollusca. It is also known as the clawed arm hook squid or the black-eyed squid. It got these names from the characteristic black eye and from its two arms with clawed hooks on the end that extend a bit further than the other arms. It is a squid in the family Gonatidae, found most commonly in the northern Pacific Ocean from Japan to California. They are one of the most abundant cephalopods off the coast of California, mostly found at deeper depths, rising during the day most likely to feed.
Histioteuthis reversa, commonly known as the reverse jewel squid or the elongate jewel squid, is a species of cock-eyed squid, so called because the eyes are dissimilar. It occurs at moderate depths in the Atlantic Ocean and the Mediterranean Sea. It is also known from the Indian Ocean.
Onychoteuthis meridiopacifica is a species of squid in the family Onychoteuthidae. Males become mature at 40 mm, and the species is believed to reach a maximum mantle length of 90 mm, the smallest species in the genus Onychoteuthis. The tentacular club reaches a length of 20-25% of the mantle length, and contains 16-19 club hooks. Arms reach 27-44% of the mantle length, and each contain 50-60 suckers. 8-12 nuchal folds are present on each side of the head. Its short, broad fins and the possession of a small number marginal suckers on the tentacular clubs of adults are distinguishing characteristics of this species. It is found off eastern Australia and probably extends into seas off Indonesia as well as east to Tonga and Vanuatu.
Taonius borealis is a glass squid belonging to the genus Taonius. It is found in the North Pacific Ocean, ranging from Japan to southern California.
Slosarczykovia is a monotypic genus of squid, its sole representative being Slosarczykovia circumantarctica. Slosarczykovia is placed in the family Brachioteuthidae.
Taonius belone is a glass squid belonging to the genus Taonius from the family Cranchiidae. It occurs in the northern subtropical and in the tropical or equatorial waters of the Pacific Ocean and the Indian Ocean.
Gonatopsis okutanii is a species of squid from the family Gonatidae from the northern Pacific Ocean. It is of uncertain taxonomic status, the presence of remnant tentacles on spent females indicate that this species does not belong in the genus Gonatopsis and the differences between this species and Gonatus makodai have led to some authorities stating that G. okutanii is a junior synonym of Eogonatus tinro. However the World Register of Marine Species still recognises Gonatopsis okutanii as the valid name for this taxon.
Gonatopsis borealis, the Boreopacific armhook squid, is a species of squid from the North Pacific Ocean. It is a member of the family Gonatidae. It is an abundant species which is currently caught mainly as a bycatch by fishing boats targeting other quarry. It is an important prey species for many commercially important species of fish, as well as for marine mammals.
Ornithoteuthis volatilis, the shiny bird squid, is a squid from the subfamily Ommastrephinae, the flying squids, of the family Ommastrephidae part of the pelagic squid order Oegopsida. It is a tropical and sub-tropical species which is widely distributed in the Indo-Pacific oceans. It is slightly larger than the closely related species Ornithoteuthis antillarum of the Atlantic Ocean.
The Antarctic flying squid is a species of squid from the subfamily Todarodinae of the family Ommastrephidae, a family of pelagic squid from the order Oegopsida. It has a circumglobal distribution in the seas around the lower latitudes of the Southern Ocean.
The European flying squid is a species of squid from the continental slope and oceanic waters of the eastern Atlantic Ocean and the Mediterranean Sea. It is the type species of the genus Todarodes, the type genus of the subfamily Todarodinae of the pelagic squid family Ommastrephidae. It is a species which is targeted by some fisheries, although it is more often a bycatch.