Squid are cephalopods in the superorder Decapodiformes with elongated bodies, large eyes, eight arms and two tentacles. 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.
Onykia robusta, also known as the robust clubhook squid and often cited by the older name Moroteuthis robusta, is a species of squid in the family Onychoteuthidae. Reaching a mantle length of 2 m (6.6 ft), it is the largest member of its family and one of the largest of all cephalopods. The tentacular clubs are slender, containing 15–18 club hooks. Arms of the species contain 50–60 suckers, and grow to 90–100% of the mantle length. It is found primarily in the boreal to Temperate Northern Pacific.
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 of the genus Onychoteuthis in 2010, it is now accepted that Onychoteuthis banksii is restricted to the central and northern Atlantic and the Gulf of Mexico while a recently described species, Onychoteuthis horstkottei, is found in the Pacific Ocean. The type locality is the Gulf of Guinea.
Mastigopsis is a genus of whip-lash squid containing one single species, Mastigopsis hjorti. Some teuthologists consider Idioteuthis synonymous with this taxon; however, genetic results indicate that this genus is not closely related with Idioteuthis but actually closer to Magnoteuthis.
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 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.
Enoploteuthis is a genus of squid in the family Enoploteuthidae. The species of Enoploteuthisare most easily recognised by having a larger tail when compared to the other genera in the Enoploteuthidae. The tail's size is emphasised not having the fins extending along its sides. In related genera there is a narrow extension of the fins along the tail. Other characteristics include the presence of suckers on the distal portion of arms IV where there at no photophores present; the tentacular club has two rows of hooks and no marginal suckers; on the buccal crown there are typical chromatophores on the aboral surface but on the oral surface there may be some light skin pigmentation. They have 9-10 photophores on the eye and they have complex photophores in the skin. In the females the Spermatangia receptacles are at the posterior junction of muscles used to retract the funnel and the muscles which retract the head. Enoploteuthis differs from other genera of the Enoploteuthidae in having two rather than three types of photophores in its integument and these are on the ventral areas of the head, funnel and mantle. All species of Enoploteuthis which have been studied have the most complex type of photophoreand seems to be a distinctive characteristic of this genus. Enoploteuthis contains the largest species in the family, attaining a mantle length of 130mm.
The neon flying squid, sometimes called the red flying squid, akaika, and red squid is a species of large flying squid in the family Ommastrephidae. They are found in subtropical and temperate oceanic waters globally.
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.
Loliolus is a genus of squid from the family Loliginidae from the Indo-Pacific region. The genus is divided into two subgenera Loliolus and Nipponololigo. They are small squids of less than 150mm in mantle length which have an expanded tentacular club. This club has 4 series of suckers. The sucker ringss have plate-like teeth which are square in shape all around them. The males' hectocotylus has a ventral crest which is created by the fusion of the protective membrane with the ventral series of papillae and this crest completely obscures the conical shape of the papillae. The mantle is rounded posteriorly and lacks the posterior tail-like lobe while the fins are positioned on the rear of the mantle and extend to the posterior tip of the mantle. Their eggs are small and the males' spermatophore has a short cement body. They do not possess photophores. The two subgenera are distinguished by the hectocotylus which in Loliolus encompasses the entire arm and there are no unmodified suckers while in Nipponololigo the arm is only partly hectocotylsed and has normal suckers at its base.
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 and Indian Oceans.
Lampadioteuthis megaleia is a small, colorful squid from the family Lycoteuthidae, it is the only species in the only genus in the monotypic subfamily Lampadioteuthinae, it is sometimes known as the wonderful firefly squid. It differs from the other species of the Lycoteuthidae mainly by having a hectocotylus in the males and by the possession of a rostrum on the gladius.
Nematolampas regalis, the regal firefly squid is a small, little known species of squid from the family Lycoteuthidae which is found in the subtropical South Pacific Ocean. This squid has a mantle length of 30mm. It may be sexually dimorphic with the males possibly having very thin elongated arms III which are increasingly thread like towards their tips where they do not have any suckers. Arms II are "normal" and have suckers along their length. The third arms have a series of photophores along their length and there is a small photophore located on each of the tips of arms I and II. The tentacles have two embedded photophores and the largest of the eye's photophores is in the centre. There is a pair of large photophores vlose to the tip of the mantle on the ventral side mantle; with no other photphores on the body except for a visceral photophore which is also near the tip. There is practically no tail. N. regalis is known only from the Kermadec Islands near New Zealand, one of the specimens was beached while the other two were caught by a trawl at a depth of 48m.
Eucleoteuthis is a monotypic genus of squid from the family Ommastrephidae, the only species is Eucleoteuthis luminosa, the striped flying squid or luminous flying squid.
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.
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.
Onychoteuthis bergii is a species of hooked squid from the family Onychoteuthidae, it was originally described by Hinrich Lichtenstein from speciemsn 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.
