Onychoteuthis horstkottei is the most recently described Onychoteuthis species. It is distinguished from congeners by having two separate smaller photophores on the ventral surface of the eyeball (where all other Onychoteuthis species have a single elongate photophore).
Diagnosis
An Onychoteuthis species...
- with tentacle club length ~24% ML.
- with spikes on the distal ventral hooks.
- with subequal-sized visceral photophores.
- with two separate ventral photophores one each eye.
Tentacle club
- Length ~24% ML, with 20–22 long, robust, strongly recurved hooks.
- Bases of hooks V7 or V8 through distal-most produced into pronounced ventral spike by ML 54 mm.
Body indices
- Arm lengths - Arms 1 ~38% ML, II-IV ~53% ML
- Fin length ~ 54% ML
- Fin width ~92% ML
- Club length ~24% ML
- Club hook numbers 20-22
- Largest hooks - Hooks V5 or V6
Photophores
- Posterior intestinal photophore circular, well defined, subequal in diameter.
- Two ocular photophores present on ventral surface of each eyeball, together spanning ~30% eye circumference.
Eastern equatorial Pacific, depth unknown (most specimens collected at surface).
Bolstad, K.S.R. 2010. Systematics of the Onychoteuthidae Gray, 1847 (Cephalopoda: Oegopsida). Zootaxa, 2696: 186 pp.
Taxonomy
- Class
- Cephalopoda
- Superorder
- Decapodiformes
- Order
- Oegopsida
- Family
- Onychoteuthidae
- Genus
- Onychoteuthis