Walvisteuthis rancureli is a small squid of under 80 mm ML as an adult. This species is easily recognized by its short, broad shape and oval fins. Another diagnostic feature of Walvisteuthis species is the short, thin, blunt rostrum that is oriented perpendicular to the gladius.

The single recognized species has a very broad geographical distribution. The type locality is the tropical Indian Ocean. The junior synonym, Walvisteuthis virilis, was taken in the temperate South Atlantic. The specimens described here are from the tropical North Pacific, and we have seen specimens from the tropical Atlantic. Rancurel (1970) described specimens from the tropical South Pacific. For an onychoteuthid, this broad distribution suggests that "Walvisteuthis rancureli" probably represents a species complex. However, squid in present collections are insufficient to define possible species differences. This is partly due to the fact that nearly all squid have been recovered from the stomachs of fish. Acidity of the fish stomach will greatly damage the horny suckers and hooks. Because W. rancureli may represent a species complex, we include exerpts from the original descriptions of Onykia rancureli and Walvisteuthis virilis:

• Onykia rancureli: Description of the holotype
• Walvisteuthis virilis: Description of the holotype

Diagnosis

An onychoteuthid ...

• Fins oval, not drawn-out posteriorly (unique character).
• with gladius visible beneath skin in dorsal midline.
• with 3 occipital folds.