Revisiting the Lepetodrilus elevatus species complex (Vetigastropoda: Lepetodrilidae), using samples from the Galapagos and Guaymas hydrothermal vent systems

摘要

The current distribution ranges of vent species result from the complex tectonic history of oceanic ridges. A growing number of DNA barcode studies report the presence of cryptic species across geological discontinuities that offset ridge systems and have gradually helped to draw a more precise picture of the historical migration pathways of vent fauna. We reexamined the phylogeny of species within the Lepetodrilus elevatus complex along the East Pacific Rise (EPR) ridge system in the light of new samples from the Galapagos Rift and the Guaymas Basin. Our analyses of mitochondrial cytochrome c oxidase subunit I gene sequences, coupled with morphological data, highlight the occurrence of a distinct lineage along the Galapagos Rift and offer new insight into the current distribution range of this species complex. Due to the absence of clear morphological diagnostic criteria and the potential overlap of these lineages at key locations, we recommend reassigning the taxon L. galriftensis to the subspecies level and maintaining the name L. elevatus for all clades along the EPR/Galapagos Rift system.