Chtenopteryx is a genus of small, muscular, midwater squid in the monotypic family Chtenopterygidae. Four species are presently recognized in the genus, but more are believed to exist.
The family Cranchiidae comprises the approximately 60 species of glass squid, also known as cockatoo squid, cranchiid, cranch squid, or bathyscaphoid squid. Cranchiid squid occur in surface and midwater depths of open oceans around the world. They range in mantle length from 10 cm (3.9 in) to over 3 m (9.8 ft), in the case of the colossal squid. The common name, glass squid, derives from the transparent nature of most species. Cranchiid squid spend much of their lives in partially sunlit shallow waters, where their transparency provides camouflage. They are characterised by a swollen body and short arms, which bear two rows of suckers or hooks. The third arm pair is often enlarged. Many species are bioluminescent organisms and possess light organs on the undersides of their eyes, used to cancel their shadows. Eye morphology varies widely, ranging from large and circular to telescopic and stalked. A large, fluid-filled chamber containing ammonia solution is used to aid buoyancy. This buoyancy system is unique to the family and is the source of their common name "bathyscaphoid squid", after their resemblance to a bathyscaphe. Often the only organ that is visible through the transparent tissues is a cigar-shaped digestive gland, which is the cephalopod equivalent of a mammalian liver. This is usually held in a vertical position to reduce its silhouette and a light organ is sometimes present on the lower tip to further minimise its appearance in the water.
The Enoploteuthidea are a family of squid comprising approximately 40 species in four genera. Most species have a mantle length ranging from 3–13 cm. Hooks are present on all arms and tentacles. The family is best known for the large array of photophores throughout the body.
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.
Oegopsida is one of the two orders of squid in the superorder Decapodiformes, in the class Cephalopoda. Together with the Myopsina, it was formerly considered to be a suborder of the order Teuthida, in which case it was known as Oegopsina. This reclassification is due to Oegopsina and Myopsina not being demonstrated to form a clade.
Lycoteuthis is a genus containing two species of squid: Lycoteuthis springeri and Lycoteuthis lorigera. They are small animals which grow up to 8 cm in length.
Abralia is a genus of squid comprising around 20 species from the family Enoploteuthidae. They are small squid which can be found in the epipelagic to mesopelagic zones while some species are found in water with shallow substrates on steep slopes on the boundary of the mesopelagic zone. They are distinguished from other members of the Enoploteuthidae by not normally having large, black photophores at the tips of arms IV, although if these are present they are not covered in black chromatophores, and having fins which extend beyond their tail. The photophores of the integument are characteristicand are found in the three types. "Lensed" photophores are a blue color with a white ring, "simple" photophores are small and violet-colored and the "complex" photophores are surrounded by small green satellite points and have a green centre. The complex photophores will frequently appear to be blue depending on their physiological state. The integument also has small black chromatophores which look like dots. They have 5-12 variably sized photophores on the eye. Either the right or left arm IV is hectocotylized.
Cranchiinae is a subfamily containing four genera of glass squids.
Taoniinae is a subfamily containing ten genera of glass squids.
Euprymna is a genus of bobtail squid comprising a number of species.
Abraliopsis is a genus of squid in the family Enoploteuthidae comprising 11 nominal species. Species are characterised by the presence of photophores on arm pair IV. Suckers are absent from this arm. The type species is Abraliopsis hoylei.
Lycoteuthis lorigera is a species of squid in the genus Lycoteuthis. They grow up to 8 cm in length.
Nematolampas venezuelensis is a squid small in size (58–88mm). This squid can be found in tropical waters off the coast of Venezuela in the Caribbean Sea, Western North Atlantic. The data for this species has been gathered from four immature squids captured in the tropical waters off the coast of Venezuela in the Caribbean Sea, Western North Atlantic.
Stigmatoteuthis is a genus of squid from the family Histioteuthidae. They occur in the Oceans from the tropics south to the temperate seas.
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.
Lycoteuthinae is a subfamily of squid from the family Lycoteuthidae. They are found in tropical and subtropical waters. They are characterised by the possession of oval photophores on the tentacles, eyeballs and viscera in all species and on the arms, head, mantle and fins in some. Some species also show strong sexual dimorphism. The subfamily contains all of the species classified under Lycoteuthidae, except for Lampadioteuthis megaleia which differs from the Lycoteuthins by the bearing of a hectocotylised arm in males.
Nematolampas is a genus of squid from the family Lycoteuthidae. The genus comprises two species both of which are known from only a few males. The type species, Nematolampas regalis has been recorded from the subtropical South Pacific and the second species, Nematolampas venezuelensis, is from the tropical western North Atlantic. The main distinguishing feature of this genus is that arms III are very elongated and thread-like and have no suckers near their tips. As only males have been captured it is not known if this feature is present in females.
Selenoteuthis is a monotypic genus of squid from the family Lycoteuthidae. Its sole species is the small tropical and subtropical North Atlantic species, Selenoteuthis scintillans, the moon squid.
Lycoteuthis springeri is a small species of rarely captured squid from the family Lycoteuthidae. It has three photophores on the posterior portion of the abdomen and the males have a long tail which bears seven deeply embedded long and thin photophores. The males also have photophores on arms II and III, as well as on the head and the mantle. The tentacular clubs and the structure of the suckers on the club and arm are not distinctive. Two of the known specimens were males which had mantle lengths of 80mm and 97mm. The type locality was in the Gulf of Mexico and the holotype was found in the stomach of a shark which was captured at 367m.
Enoploteuthoidea is a superfamily of squid in the order Oegopsida.
