Discovery of the fourth species of the enigmatic chiroteuthid squid Asperoteuthis (Cephalopoda: Oegopsida) and extension of the range of the genus to the South Atlantic

摘要

A new species of deepwater squid Asperoteuthis nesisi is described based on a single specimen from the Southwest Atlantic. The new species is characterized by rather thin but muscled mantle and arms, and a wide ovoid funnel-locking apparatus with weak tragus and well-developed antitragus. Peculiar integumental tubercles are present both on the mantle and head. The largest arm suckers have chitinous rings with 12–14 separate sharp triangular teeth distally and a flat thin ridge proximally. Based on the external morphology, A. nesisi n. sp. is more closely related to A. acanthoderma than to A. mangoldae. Two specimens of ‘Mastigoteuthis? A’ reported previously from waters of South Georgia probably belong to A. nesisi n. sp. Our finding extends the range of the genus Asperoteuthis from the tropical and temperate Pacific to the sub-Antarctic Atlantic, supporting a cosmopolitan distribution of this genus of deepwater squid.