Introduction

Species of Planctoteuthis are usually rather small and very fragile deep-sea squids that are often badly damaged during capture. As a result, few species have been described. Unlike other chiroteuthids, the subadult retains the peculiar doratopsid paralarval tentacular club. Roper and Young (1967) suggest that Planktoteuthis is a neotenic doratopsis.

Diagnosis

A chiroteuthid ...

• with antitragus but no tragus in oval funnel locking-apparatus.
• with a compact club not divided into proximal and distal regions by structure of protective membranes.
• without funnel valve.
• without photophores.