Octopoteuthis
Octopoteuthis is a genus of squid, one of the two referred to as octopus squid, the other being Taningia, its sister genus. Both Octopoteuthis and Taningia are characterized by their lack of tentacles for the majority of their life cycle, which led to their common name.
Classification
This genus is separated from Taningia by adults possessing spindle-shaped photophores on the tips of all 8 arms ; the presence of additional photophores embedded in the mantle, head, and arms ; and a smaller adult size, with mantle lengths 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 paralarvae 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 at ML.The species limits of the genus are in need of further research; for example, some authorities have stated that the Mediterranean species Octopoteuthis sicula is apparently the senior synonym 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:
- Octopoteuthis danae Joubin, 1931
- Octopoteuthis deletron Young, 1972
- Octopoteuthis indica Naef, 1923
- Octopoteuthis longiptera * Akimushkin, 1963
- Octopoteuthis megaptera
- Octopoteuthis nielseni Robson, 1948
- Octopoteuthis rugosa Clarke, 1980
- Octopoteuthis sicula Rüppell, 1844, Ruppell's octopus squid
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 groups. These species recovered in the study are: