''Gonatopsis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of squid from the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Gonatidae The Gonatidae, also known as armhook squid, are a family of moderately sized squid. The family contains about 19 species in three genera, widely distributed and plentiful in cold boreal waters of the Pacific Ocean. At least one species is known f ...

. They are characterised by the loss of their

tentacles 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 mainl ...

by the time they have reach the subadult stage. They have

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 ...

which have two series of hooks along the midline of the oral surface arms, the radula has five or seven teeth, the mantle can be muscular or flabby, fins are rhomboid or arrow shaped and they lack

photophore A photophore is a glandular organ that appears as luminous spots on various marine animals, including fish and cephalopods. The organ can be simple, or as complex as the human eye; equipped with lenses, shutters, color filters and reflectors, ...

s. They are found in the North Pacific.

Species

The following species have been classified as belonging to ''Gonatopsis'': *'' Gonatopsis borealis'' Sasaki, 1923 *'' Gonatopsis japonicus'' Okiyama, 1969 *'' Gonatopsis makko'' Okutani & Nemoto, 1964 *'' Gonatopsis octopedatus'' Sasaki, 1920 *'' Gonatopsis okutanii'' * Nesis, 1972 The species listed above with an asterisk (*) is a ''

taxon inquirendum In biological classification, a ''species inquirenda'' is a species of doubtful identity requiring further investigation. The use of the term in English-language biological literature dates back to at least the early nineteenth century. The term t ...

'' and needs further study to determine if it is a valid species or a synonym.

References

Squid Cephalopod genera {{squid-stub