''Octopoteuthis'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...

, one of the two referred to as octopus squid (

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Octopoteuthidae The Octopoteuthidae are a family of squid comprising two genera. The family is characterized by tentacles which cease to grow after the paralarval stage which leads to the adult having eight arms; thus, members of this family are commonly named ...

), the other being ''

Taningia ''Taningia'' is a genus of squid, one of the two referred to as octopus squid (family Octopoteuthidae), the other being ''Octopoteuthis'', its sister genus. Both ''Octopoteuthis'' and ''Taningia'' are characterized by their lack of tentacles fo ...

'', its sister genus. Both ''Octopoteuthis'' and ''Taningia'' are characterized by their lack of

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s for the majority of their life cycle, which led to their

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

Classification

This genus is separated from ''Taningia'' by adults possessing spindle-shaped

photophore A photophore is a specialized anatomical structure found in a variety of organisms that emits light through the process of boluminescence. This light may be produced endogenously by the organism itself (symbiotic) or generated through a mut ...

s on the tips of all 8 arms (as opposed to a globular pair on a single arm pair in ''Taningia''); the presence of additional photophores embedded in the mantle, head, and

arms Arms or ARMS may refer to: *Arm or arms, the upper limbs of the body Arm, Arms, or ARMS may also refer to: People * Ida A. T. Arms (1856–1931), American missionary-educator, temperance leader Coat of arms or weapons *Armaments or weapons **Fi ...

(the location and sizes of which vary among the species); and a smaller adult size, with mantle lengths (ML) of up to , but typically not exceeding . This genus possesses two rows of arm hooks on each arm pair, which may already be present at 2.5 mm ML. The

paralarva Coleoidea or Dibranchiata is one of the two subclasses of cephalopod molluscs containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e. octopus, squid and cuttlefish). Unlike its extant sister group Nautiloidea ...

e of this genus possess "weak", gelatinous tentacle stalks, the tentacles themselves are lost at about ML. Paired photophores may be present on the

ink sac An ink sac is an anatomical feature that is found in many cephalopod mollusks used to produce the defensive cephalopod ink. With the exception of nocturnal and very deep water cephalopods, all Coleoidea (squid, octopus and cuttlefish) which dwell ...

at ML. The species limits of the genus are in need of further research; for example, some authorities have stated that the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

species '' Octopoteuthis sicula'' is apparently the

senior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

of '' Octopoteuthis danae'' and that it is very closely related to, or possibly conspecific with, '' Octopoteuthis megaptera''. The following species are recognised by the

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

: *'' Octopoteuthis danae'' Joubin, 1931 *'' Octopoteuthis deletron''

Young Young may refer to: * Offspring, the product of reproduction of a new organism produced by one or more parents * Youth, the time of life when one's age is low, often meaning the time between childhood and adulthood Music * The Young, an America ...

, 1972 *'' Octopoteuthis indica'' Naef, 1923 *'' Octopoteuthis longiptera'' * Akimushkin, 1963 *'' Octopoteuthis megaptera'' ( Verrill, 1885) *'' Octopoteuthis nielseni'' Robson, 1948 *'' Octopoteuthis rugosa'' Clarke, 1980 *'' Octopoteuthis sicula'' Rüppell, 1844, Ruppell's octopus squid Species marked with an asterisk (*) is a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

'' and may not be a valid taxon Additional species were recovered by a 2019 study, but they have not been corroborated by WoRMS or SeaLifeBase. The study also separates Octopoteuthis into 4

species group In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

s. These species recovered in the study are: *'' Octopoteuthis fenestra'' *'' Octopoteuthis laticauda'' *'' Octopoteuthis leviuncus'' *''Octopoteuthis sp.'' "IO" *''Octopoteuthis sp.'' "Giant Pacific" *''Octopoteuthis sp.'' "Giant Atlantic"

References

{{Taxonbar, from=Q1223163 Octopoteuthidae Bioluminescent molluscs