Review of the systematic taxonomy of "Todaropsis eblanae" and its position within Ommastrephid squids

Abstract

The lesser flying squid Todaropsis eblanae belongs to the family Ommastrephidae, which represents an important fishing resource. Surprisingly, it is sometimes confused in the Mediterranean markets with the broadtail shortfin squid Illex coindetti due to their external morphological resemblance. Literature review about T. eblanae classified the species firstly within the subfamily Illicinae, later within the subfamily Todarodinae and recently was proposed as the only member of its own subfamily. The present study, attempts to add new information and new characters to help in the subfamilies classifications and place T. eblanae in its correct systematic position. The main embryonic developmental characters and the spermatozoa morphology have been analyzed here for the first time, providing new comparative tools to evaluate the place of the species among the ommastrephid squid family. The different own features or apomorphies recognized in this study for T.eblanae among studied ommastrephids are: the largest size of the hatchlings, with presence of arm III; the gills strongly developed during embryo development, with high number of leafleets at hatching; the largest flagellar length of the biflagellate spermatozoa and the hectocotylized arms with basal chitinous crests. The study confirmed the inclusion of T. eblanae in its own monotypic subfamily, Todaropsinae. The new diagnosis characters of the species determined here will help to clarify the systematic position of T. eblanae from an integrative taxonomy approach, improving our knowledge on a species with interest to fisheries.