Boreal Clubhook Squid

Onychoteuthis borealijaponica Okada, 1927

DIAGNOSIS.—Mantle muscular but rather thin. Fins rhomboidal, length 55%–60% ML, width 65%–75% ML, apical angle 80°–90°. Nuchal folds 8 or 9 pairs. Arm formula II = III = IV > I, length 35%–45% ML. Tentacle club slightly expanded, length 20%–30% ML, 13–15 small suckers on dactylus, 25–27 hooks on manus in 2 rows, well-defined fixing apparatus with 8–10 suckers and 7–9 pads. Large luminous patch on ventral periphery of each eye. Two oval light organs in ventral mantle cavity, 1 on ink duct behind anal papilla, 1 on ink sac, with intervening silver, iridescent band; former much smaller than latter. Large species maturing at about 250 mm ML in males and about 300–350 mm ML in females.

ORIGINAL DESCRIPTION.—Okada, 1927:4.

TYPE LOCALITY.—Japan.

DEPOSITION OF TYPE.—Holotype: Not known.

Paratypes: None.

DISTRIBUTION.—Far northern Pacific, migrating from south to subarctic waters for feeding during summer and returning to subtropical waters for spawning in fall and winter (Naito et al., 1977; Kubodera et al., 1983; Murata et al., 1986).

Onychoteuthis borealijaponica, the boreal clubhook squid, is a species of squid in the family Onychoteuthidae. It is the largest member of the genus Onychoteuthis, reaching a mantle length of 30 cm in males and 37 cm in females. Maturity is reached at 250 mm for males, and 300–350 mm in females. There are 24–27 hooks on each club, which is more than any other species in the genus Onychoteuthis. It is a pelagic species native to the North Pacific, although it migrates into Subarctic waters during the summer from its more southerly winter spawning grounds.

epipelagic