A squid is a mollusc 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 these criteria. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin.
The Mastigoteuthidae, also known as whip-lash squid, are a family of small deep-sea squid. Approximately 20 known species in six genera are represented, with members found in both the mesopelagic and bathypelagic zone of most oceans. Originally described by Verill in 1881, it was later lowered by Chun (1920) to a subfamily (Mastigoteuthinae) of the Chiroteuthidae. However, Roper et al. (1969) raised it back to the family level, and this has not been changed since. The taxonomy of this family is extremely unstable, and there have been at times one genus, two genera and four subgenera(Salcedo-Vargas & Okutani, 1994), two genera and several 'groups', five genera and one species with an uncertain placement, or six genera.
The hooked squid, family Onychoteuthidae, currently comprise about 20–25 species, in six or seven genera. They range in mature mantle length from 7 cm to a suggested length of 2 m for the largest member, Onykia robusta. The family is characterised by the presence of hooks only on the tentacular clubs, a simple, straight, funnel–mantle locking apparatus, and a 'step' inside the jaw angle of the lower beak. With the exception of the Arctic Ocean, the family is found worldwide.
Taoniinae is a subfamily containing ten genera of glass squids.
Cranchia scabra is a species of glass squid. It is the only species in the genus, and is fairly small. They reside in the epipelagic zones of the tropical Atlantic. The genus also contains bioluminescent species. Cranchia scabra are named after John Cranch who first described this species.
Onykia ingens, the greater hooked squid, is a species of squid in the family Onychoteuthidae. It occurs worldwide in subantarctic oceans.
Ancistroteuthis lichtensteinii, also known as the angel clubhook squid or simply angel squid, is a species of squid in the family Onychoteuthidae and the sole member of the genus Ancistroteuthis. It grows to a mantle length of 30 cm. It lives in the western Mediterranean Sea, subtropical and tropical eastern Atlantic Ocean and western north Atlantic Ocean. Its diet include mesopelagic fish and pelagic crustaceans. It is sometimes taken as bycatch by commercial fisheries, but is not a targeted species.
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.
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 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.
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 females. Maturity is reached at 250 mm for males, and 300–350 mm in females. There are 24–27 hooks on each club, which is more than any other species in the genus Onychoteuthis. It is a pelagic species native to the North Pacific, although it migrates into Subarctic waters during the summer from its more southerly winter spawning grounds.
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. The species is known to have a mantle length of at least 122 mm for females and 127 mm for males. Each tentacle has 22 club hooks, measuring approximately 30 mm in mature specimens.
Pterygioteuthis giardi is a species of squid in the family Pyroteuthidae. It is known as the roundear enope squid. The specific name honors the French zoologist and marine biologist Alfred Mathieu Giard (1846-1908).
Abraliopsis morisii is a species of bioluminescent squid in the family Enoploteuthidae. The species occurs in tropical to warm temperate waters in the Atlantic Ocean, including the Gulf of Mexico and the Mediterranean Sea. It can be found in the epipelagic and mesopelagic zones. Jean Baptiste Vérany described the species in 1839 and it reaches lengths of 25 to 33 millimetres. It is rated as least concern by the International Union for Conservation of Nature (IUCN).
The colossal squid is the largest member of its family Cranchiidae, the cockatoo or glass squids, with its second largest member being Megalocranchia fisheri. It is sometimes called the Antarctic cranch squid or giant squid and is believed to be the largest squid species in terms of mass. It is the only recognized member of the genus Mesonychoteuthis and is known from only a small number of specimens. The species is confirmed to reach a mass of at least 495 kilograms (1,091 lb), though the largest specimens—known only from beaks found in sperm whale stomachs—may perhaps weigh as much as 600–700 kilograms (1,300–1,500 lb), making it the largest known invertebrate. Maximum total length has been estimated between 10 metres (33 ft) and 14 metres (46 ft) but the former estimate is more likely. The colossal squid has the largest eyes of any known creature ever to exist, with an estimated diameter of 27–30 cm (11–12 in) to 40 cm (16 in) for the largest collected specimen.
Teuthowenia megalops, sometimes known as the Atlantic cranch squid, is a species of glass squid from the subarctic and temperate waters of the northern Atlantic Ocean. They are moderately sized squid with a maximum mantle length of 40 cm (16 in). Their very large eyes are the source for the specific name megalops. Like other members of the genus Teuthowenia, they are easily recognizable by the presence of three bioluminescent organs (photophores) on their eyeballs.
Cephalopod fins, sometimes known as wings, are paired flap-like locomotory appendages. They are found in ten-limbed cephalopods as well as in the eight-limbed cirrate octopuses and vampire squid. Many extinct cephalopod groups also possessed fins. Nautiluses and the more familiar incirrate octopuses lack swimming fins. An extreme development of the cephalopod fin is seen in the bigfin squid of the family Magnapinnidae.
Enoploteuthis leptura, the hooked enope squid, is a species of squid from the family Enoploteuthidae. It is the type species of the genus Enoploteuthis, which is in turn the type genus of the Enoploteuthidae.
Lampadioteuthis megaleia is a small, colorful squid, the only species in the only genus in the monotypic family Lampadioteuthidae. It is sometimes known as the wonderful firefly squid. It was formerly classified in the family Lycoteuthidae, but differs from them mainly by having a hectocotylus in the males and by the possession of a rostrum on the gladius.
Ornithoteuthis antillarum, the Atlantic bird squid, is a species of flying squid from the family Ommastrephidae which is found in the warmer waters of the Atlantic Ocean. This species is an important component of the diet of many species of fish and of cetaceans. It is taken as a bycatch in fisheries but has the potential to be commercially important if appropriate fishing methods can be developed.
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 Onychoteuthis. Until recently it was considered to be a junior synonym of Onychoteuthis banksii, but a re-examination of the type material, the lectotype and paralectotype which are deposited in the Natural History Museum, Berlin, showed that there were morphological differences which supported the status of O. bergii as a valid species. The species is found in the eastern South Atlantic and Indian Oceans.
