''Onychoteuthis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

in the family

Onychoteuthidae The hooked squid, family Onychoteuthidae, currently comprise about 20–25 species (several known from only single life stages and thus unconfirmed), in six or seven genera. They range in mature mantle length from 7 cm to a suggested length ...

. 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 ...

is ''

Onychoteuthis bergii ''Onychoteuthis bergii'' is a species of hooked squid from the family Onychoteuthidae. The species was originally described by Hinrich Lichtenstein from specimens taken near the Cape of Good Hope and is the type species of the genus '' Onychote ...

''. While the genus is found worldwide in

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

oceans, they can also occur in the

North Pacific Ocean North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' is ...

. There were previously considered to be four species in the genus but there are now considered to be roughly 10. These squid are frequently observed in the surface waters at night and they are often caught using dipnet at nightlight stations. The young squid are usually the only specimens captured using standard midwater trawls, the older squid are apparently able to avoid the trawls. They can, however be collected from the air as individuals are able to leap high out of the water, sometimes even landing on the deck of a ship.

Anatomy

Most

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 ...

belonging to the genus have a mantle length of under 200 mm, however the larger members may measure over 300 mm. The species in this genus have a densely muscular, cylindrical mantle which is tapered posteriorly into a pointed tail. Their skin is smooth and has no warts or wrinkles. The

gladius ''Gladius'' () is a Latin word meaning "sword" (of any type), but in its narrow sense it refers to the sword of ancient Roman foot soldiers. Early ancient Roman swords were similar to those of the Greeks, called '' xiphe'' (plural; singular ''xi ...

can be seen through the skin along the midline of the back. The fins are rhomboid in shape, heart shape or arrow shaped and are pointed posteriorly. The species of ''Onychoteuthis'' have 8-10 prominent nuchal folds. Their

tentacular club All cephalopods possess flexible limbs extending from their heads and surrounding their beaks. These appendages, which function as muscular hydrostats, have been variously termed arms, legs or tentacles. Description In the scientific l ...

s have 2 central series of 19-27 large, strong hooks on their manus and the adults either have no lateral sucker series no marginal series of suckers. or they are vestigial. The

chitin Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chit ...

ous rings of the suckers on the

arms Arms or ARMS may refer to: *Arm or arms, the upper limbs of the body Arm, Arms, or ARMS may also refer to: People * Ida A. T. Arms (1856–1931), American missionary-educator, temperance leader Coat of arms or weapons *Armaments or weapons **Fi ...

is smooth, with no teeth. They have

photophore A photophore is a glandular organ that appears as luminous spots on various marine animals, including fish and cephalopods. The organ can be simple, or as complex as the human eye; equipped with lenses, shutters, color filters and reflectors, ...

s in their mantle cavity with a small one placed anteriorly on the

ink sac An ink sac is an anatomical feature that is found in many cephalopod mollusks used to produce the defensive cephalopod ink. With the exception of nocturnal and very deep water cephalopods, all Coleoidea (squid, octopus and cuttlefish) which dwell ...

, another near the anus; a large one placed posteriorly on the intestine and a bilobed photophore located on the ventral surface of each eye.

Species

The following species are included in the genus: *'' Onychoteuthis aequimanus'' Gabb, 1868 *''

Onychoteuthis banksii ''Onychoteuthis banksii'', the common clubhook squid, is a species of squid in the family Onychoteuthidae. It is the type species of the genus '' Onychoteuthis''. This species was thought to have a worldwide distribution but with the revision o ...

'' (

Leach Leach may refer to: * Leach (surname) * Leach, Oklahoma, an unincorporated community, United States * Leach, Tennessee, an unincorporated community, United States * Leach Highway, Western Australia * Leach orchid * Leach phenotype, a mutation in ...

, 1817), common clubhook squid *''

'' Lichtenstein, 1818 *''

Onychoteuthis borealijaponica ''Onychoteuthis borealijaponica'', the boreal clubhook squid, is a species of squid in the family Onychoteuthidae. It is the largest member of the genus '' Onychoteuthis'', reaching a mantle length of 30 cm in males and 37 cm in fema ...

Okada Okada (written: 岡田 literally "hill rice-paddy") is a Japanese surname. Notable people with the name include: * , Japanese painter * Doris Okada Matsui, American politician of the Democratic Party * , Japanese painter in the Edo period * , Japa ...

, 1927, boreal clubhook squid *''

Onychoteuthis compacta ''Onychoteuthis compacta'' is a species of squid in the family Onychoteuthidae, known to occur in Hawaiian waters. as well as in other areas of the Central Pacific and western north-central Atlantic, it probably has a circumglobar distribution. ...

'' (

Berry A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...

, 1913) *''

Onychoteuthis horstkottei ''Onychoteuthis'' is a genus of squid in the family Onychoteuthidae. The type species is ''Onychoteuthis bergii''. While the genus is found worldwide in tropical and subtropical oceans, they can also occur in the North Pacific Ocean. There were p ...

'' Bolstad, 2010 *''

Onychoteuthis lacrima ''Onychoteuthis'' is a genus of squid in the family Onychoteuthidae. The type species is '' Onychoteuthis bergii''. While the genus is found worldwide in tropical and subtropical oceans, they can also occur in the North Pacific Ocean. There we ...

'' Bolstad & Seki, 2008 *''

Onychoteuthis meridiopacifica ''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 '' Onychote ...

'' Rancurel & Okutani, 1990 *''

Onychoteuthis mollis ''Onychoteuthis'' is a genus of squid in the family Onychoteuthidae. The type species is '' Onychoteuthis bergii''. While the genus is found worldwide in tropical and subtropical oceans, they can also occur in the North Pacific Ocean. There we ...

'' ( Appellöf, 1891) *'' Onychoteuthis prolata'' Bolstad, Vecchione &

Young Young may refer to: * Offspring, the product of reproduction of a new organism produced by one or more parents * Youth, the time of life when one is young, often meaning the time between childhood and adulthood Music * The Young, an American roc ...

, 2008 There are also two species which are considered '' taxa inquirendum'' and up to 11 which are classed as '' nomen dubia.

References

{{Taxonbar, from=Q3166929 Squid Cephalopod genera Bioluminescent molluscs