Systematics and distribution of the squid genus Pterygioteuthis (Cephalopoda: Oegopsida) in the eastern tropical Pacific Ocean

Abstract

Understanding speciation in pelagic marine organisms is difficult due to poor knowledge of their systematics and distribution. This paper examines the systematics of the squid genus Pterygioteuthis and its distribution and speciation in the eastern tropical Pacific Ocean. A morphology-based phylogenetic analysis identifies two clades: the P. giardi group (P. giardi giardi and P. giardi hoylei) and the P. gemmata group (P. gemmata and P. microlampas). Based on its morphological and biogeographic differences from P. giardi giardi, the subspecies P. giardi hoylei (fide Nesis, 1987) is elevated to species status and a neotype designated. Also, to clarify taxonomic issues in the P. gemmata group, a neotype is designated for P. microlampas Berry, 1913. These strictly pelagic taxa have distinct distributions; P. hoylei is the only pyroteuthid to occur in the relatively isolated eastern tropical Pacific (ETP), while P. giardi inhabits the temperate north and south Pacific (excluding the ETP) and the Atlantic. Pterygioteuthis microlampas is known only from off the Hawaiian Islands and New Zealand, while P. gemmata extends throughout the temperate Pacific (excluding the ETP) and Atlantic. This study represents the first detailed cladistic analysis of Pyroteuthidae and generates new hypotheses regarding speciation in the open ocean.