Cephalopods from the Netherlands Indian Ocean Programme (NIOP)- II. Mastigoteuthid lineage and related forms

Seven species of bathypelagic squids from the West Indian Ocean are described. Two species from the chiroteuthid lineage are recorded: Pianktoteuthis sp. and Chiroteuthis mega. The family Mastigoteuthidae is divided in two genera: Idioteuthis and Mastigoteuthis. As members of the former are Idioteuthis danae (=Echinoteuthis danae) and two species new to science, and for the latter Mastigoteuthis glaukopis and Mastigoteuthis grimaldii. The mastigoteuthid lineage is defined by: 1) short neck and brachial pillar; 2) whip-like tentacle; 3) ovate pseudoconus in cross section view, and 4) arm formula: IV>II>III≥I. The family Mastigoteuthidae as now defined consist of seventeen species.