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 is known only from larval, paralarval, and juvenile specimens, some authorities believe adult specimens have also been seen. Several videos have been taken of animals nicknamed the "long-arm squid", which appear to have a similar morphology. Since none of the seemingly adult specimens has ever been captured or sampled, it remains uncertain if they are of the same genus or only distant relatives.
Grimpoteuthis is a genus of pelagic umbrella octopuses known as the dumbo octopuses. The name "dumbo" originates from their resemblance to the title character of Disney's 1941 film Dumbo, having a prominent ear-like fin which extends from the mantle above each eye. There are 15 species recognized in the genus. Prey include crustaceans, bivalves, worms and copepods. The average life span of various Grimpoteuthis species is 3 to 5 years.
Taningia danae, the Dana octopus squid, is a species of squid in the family Octopoteuthidae. It is one of the largest known squid species, reaching a mantle length of 1.7 m (5.6 ft) and total length of 2.3 m (7.5 ft). The largest known specimen, a mature female, weighed 161.4 kg (356 lb).
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 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.
Moroteuthopsis longimana, also known as the giant warty squid or longarm octopus squid, is a large species of hooked squid. It attains a mantle length of at least 85 cm and probably over 1.15 m. The largest complete specimen of this species, measuring 2.3 m in total length, was found in Antarctica in 2000.
Pareledone is a genus of octopuses in the family Megaleledonidae.
Thaumeledone is a genus of octopuses in the family Octopodidae found in deep waters in the Southern Hemisphere.
Histioteuthis bonnellii, the umbrella squid, is a species of cock-eyed squid belonging to the family Histioteuthidae.
Muusoctopus levis is a species of octopus in the family Enteroctopodidae. It was first described by William Evans Hoyle in 1885 in an article in the Annals and Magazine of Natural History detailing the new species of octopus found on HMS Challenger as part of the Challenger expedition; the type specimen was retrieved from the Southern Ocean. The species is found in subantarctic waters in the Southern Ocean, particularly surrounding Heard Island and Kerguelen Island, but specimens comparable to M. levis have also been found at the Antarctic Peninsula.
Thaumeledone gunteri is a species of small, benthic, deep-sea octopus found in the bathyal zone in the Southern Ocean near South Georgia.
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.
Louise Allcock is a British researcher, best known for her work on ecology and evolution of the cephalopods of the Southern Ocean and deep sea. She is the editor of the Zoological Journal of the Linnean Society.
Megaleledonidae is a family of octopuses in the superfamily Octopodoidea. It was formerly placed in the family Octopodidae sensu lato as the subfamily Megaleledoninae but more recent studies have raised this taxon as a valid family.
Bathypurpurata is a genus of incirrate octopus in the family Megaleledonidae from the Antarctic Ocean. The genus has only one species, Bathypurpurata profunda, a small purple octopus which lacks an ink sac and has a single row of suckers and a very large salivary gland. It was described in 2005 from a type specimen caught between the Antarctic Peninsula and the South Shetland Islands.
Muusoctopus is a cosmopolitan genus of deep-sea octopus from the family Enteroctopodidae. These are small to medium-sized octopuses which lack an ink sac. Recent work has suggested that these octopuses originated in the North Atlantic and subsequently moved into the North Pacific while the species in the Southern Hemisphere are descended from multiple invasions from northern oceans.
Nototeuthis is a monotypic genus of squid, in the family Neoteuthidae. The only species in this genus is Nototeuthis dimegacotyle . This species is characterised by short tentacular clubs, less than 40% of the length of the mantle, and relatively long fins, which are approximately 60% of the mantle length. The tentacle clubs have two greatly enlarged suckers on distal portion of the manus, which distinguish N. dimegacotyle from other members of the Neoteuthidae. Few specimens of this species are currently known. Specimens have been collected from the south eastern Pacific Ocean, off Chile, between the Southern Subtropical and the Antarctic Polar frontal zones. This species is mesopelagic to bathypelagic and can be found from near the surface to a depth of ~500m.
Cirroctopus antartica is a species of deep-sea octopus known from only two specimens, both collected around the Antarctic Peninsula. Its shell is like the letter "U" in shape. It is possible, though not certain, that C. antarctica is a synonym of C. glacialis.
Grimpoteuthis challengeri is a species of large octopus living in the abyssal zone.
Opisthoteuthis extensa is a species of octopus found off the west coast of Sumatra, an Indonesian island. It lives at a recorded depth of 768 m (2,520 ft). O. extensa lives in a benthic habitat, like many other cirrate octopuses. It occupies a deep part of the ocean where little sunlight penetrates.
