A new species of the Y-larva genus Hansenocaris Ito, 1985 (Crustacea: Thecostraca: Facetotecta) from the Azores, with notes on its morphology and biogeography

A new facetotectan species, described herein as Hansenocaris spiridonovi Kolbasov, Savchenko et Hoeg sp.n. and based on its cypridiform stage, was found in the plankton off Azores Islands. We employed scanning electron microscopy to document the fine-scale external morphology of this species. We discuss the findings of facetotectan larvae showing cosmopolitan distribution of these crustaceans. The presence of Y-cyprid exuviae in plankton, findings of y-larvae in the deep sea plankton, occurrence in the oceanic plankton, as well as their permanent presence in the tropical waters may evidence on a pelagic host.

Automated summary

A new facetotectan species, Hansenocaris spiridonovi, was discovered in the plankton off Azores Islands. The fine-scale external morphology of this species was documented using scanning electron microscopy. The findings suggest a cosmopolitan distribution of facetotectan larvae and potential pelagic hosts.