Spirula spirula is a species of deep-water squid-like cephalopod mollusk. It is the only extant member of the genus Spirula, the family Spirulidae, and the order Spirulida. Because of the shape of its internal shell, it is commonly known as the ram's horn squid or the little post horn squid. Because the live animal has a light-emitting organ, it is also sometimes known as the tail-light squid.
Bigfin squids are a group of rarely seen cephalopods with a distinctive morphology. They are placed in the genus Magnapinna and family Magnapinnidae. Although the family was described only from larval, paralarval, and juvenile specimens, numerous video observations of much larger squid with similar morphology are assumed to be adult specimens of the same family.
Magnapinna atlantica, previously known as "Magnapinna sp. A", is a species of bigfin squid known from only two specimens collected in the northern Atlantic Ocean. It is characterised by several unique morphological features: the tentacle bases are narrower than adjacent arm bases, the proximal tentacle lacks suckers but possesses glandular structures, and the animal's pigment is contained mostly in functional chromatophores.
Magnapinna pacifica is a species of bigfin squid known only from three immature specimens; two caught at a depth of less than 300 m (980 ft) and one from a fish stomach. M. pacifica is the type species of the genus Magnapinna. It is characterised primarily by its proximal tentacles, which are wider than adjacent arms and bear numerous suckers.
Magnapinna talismani is a species of bigfin squid known only from a single damaged specimen. It is characterised by small white nodules present on the ventral surface of its fins.
Magnapinna sp. B is an undescribed species of bigfin squid known only from a single immature specimen collected in the northern Atlantic Ocean.
Magnapinna sp. C is an undescribed species of bigfin squid known only from a single specimen of 79-millimetre (3.1 in) mantle length (ML) collected in the southern Atlantic Ocean and held in the Natural History Museum.
Choneteuthis tongaensis is a species of bobtail squid native to the waters around the Tonga Islands in the southern Pacific Ocean. It is known from only three specimens. Of these, the holotype is the largest, at 33.8 mm mantle length (ML). C. tongaensis is characterised by several distinct morphological features: the mantle is free from the head in the nuchal region, a large, circular visceral photophore and ventral shield are present on the ventral surface of the ink sac, and the broad keel extends the full length of the club.
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.
Promachoteuthis sulcus is a species of promachoteuthid squid. It is distinguished from related taxa on the basis of several morphological features: Nuchal fusion between the head and mantle, much larger size of arm-suckers compared to club-suckers, greater width of tentacle-base than arm-base, a recessed club-base, and the presence of an aboral tentacle-groove.
The gladius, or pen, is a hard internal bodypart found in many cephalopods of the superorder Decapodiformes and in a single extant member of the Octopodiformes, the vampire squid. It is so named for its superficial resemblance to the Roman short sword of the same name, and is a vestige of the ancestral mollusc shell, which was external. The gladius is located dorsally within the mantle and usually extends for its entire length. Composed primarily of chitin, it lies within the shell sac, which is responsible for its secretion. Some species, like the bigfin reef squid, still has a gladius with some degree of mineralization.
All extant cephalopods have a two-part beak, or rostrum, situated in the buccal mass and surrounded by the muscular head appendages. The dorsal (upper) mandible fits into the ventral (lower) mandible and together they function in a scissor-like fashion. The beak may also be referred to as the mandibles or jaws. These beaks are different from bird beaks because they crush bone while most bird beaks do not.
Illex coindetii, commonly known as the southern shortfin squid or broadtail shortfin squid, is a species of neritic squids in the family Ommastrephidae. They are found in the Mediterranean Sea and on both sides of the north Atlantic Ocean.
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.
Cephalopods exhibit various dermal structures on their mantles and other parts. These may take the form of conspicuous warts, cushions, papillae or scales, though in many species they are microscopic tubercles. The most elaborate forms are found among the oceanic squid of the order Teuthida.
Uroteuthis is a genus of 14 species of common inshore squids of the Indo-West Pacific and is further subdivided into 3 subgenera. The members of the genus Uroteuthis are the only squids of the family Loliginidae that possess photophores and all species in the genus have a pair of photophore organs on the ventral surface of their ink sac either side of their intestine.
The purpleback flying squid or purpleback squid is a species of cephalopod in the family Ommastrephidae, occurring in the Indo-Pacific. It is considered one of the most abundant large squids.
Richard E. Young is a teuthologist. He is an Emeritus Professor of Oceanography at the University of Hawaii's School of Ocean and Earth Science and Technology.
Histioteuthis meleagroteuthis is a species of small to medium squids that have a dark, wine-red skin pigment. Females at maturity average at 114 mm (4.5 in) in length, while males at maturity average at 65 to 102 mm in length. This species is characterized by tubercles, photophores, and asymmetric features. This species can be found in circumglobal, mesopelagic waters.
