Onychoteuthis prolata

Onychoteuthis prolata was recently disambiguated from the O. banksii complex. Young and Harman (1987) described the paralarva (species B) from Hawaiian waters; later ontogenetic stages were formally described by Bolstad, Vecchione & Young in Bolstad (2008). The most distinctive feature of this species is the tentacle club, which is extremely long for an Onychoteuthis (35-40% ML).

Diagnosis

An Onychoteuthis species...

with tentacle club length 35-40% ML.
without spikes on the distal ventral hooks.
with chromatophores along the ventral ridge on the oral surface of the tentacle stalk.
with chromatophores on all portions of the mantle ventrally (no 'bald spot').
without fleshy knobs on the distal margin of the arm suckers.

Tentacle club

Length ~36% ML, with 20–23 long, robust, strongly recurved hooks.
Distal-most ventral hook bases not produced into spike.
Chromatophores present across oral face of tentacle stalk proximal to carpus and along oro-ventral tentacle stalk ridge (arrows in second image below).

Photophores

1. Two circular intestinal photophores present. Anterior photophore 50-75% diameter of posterior photophore.
2. Ocular photophore a long whitish patch on ventral surface of each eyeball.

Measurements of holotype

Mantle length - 135 mm
Arm lengths - 53-71 mm
Fin length - 81 mm
Fin width - 89 mm
Club length - 54 mm (left)
Club hook numbers - 23
Largest hooks - Hooks V5 and V6

Onychoteuthis prolata. Arrows indicate chromatophores present across oral face of tentacle stalk proximal to carpus and along oro-ventral tentacle stalk ridge. © K.S. Bolstad

Bolstad, K.S. 2008. Two new species and a review of the squid genus Onychoteuthis Lichtenstein, 1818 (Oegopsida: Onychoteuthidae) from the Pacific Ocean. Bulletin of Marine Science, 83: 481–529.

Young, R.E.; Harman, R.F. 1987. Descriptions of the larvae of three species of the Onychoteuthis banksii complex from Hawaiian waters. Veliger 29(3):313–321.

Overview

Diagnosis

Identification

References

Taxonomy