Phylogeny of sea hares in the Aplysia clade based on mitochondrial DNA sequence data

Sea hare species within the Aplysia clade are distributed worldwide. Their phylogenetic and biogeographic relationships are, however, still poorly known. New molecular evidence is presented from a portion of the mitochondrial cytochrome oxidase c subunit 1 gene (cox1) that improves our understanding of the phylogeny of the group. Based on these data, a preliminary discussion of the present distribution of sea hares in a biogeographic context is put forward. Our findings are consistent with only some aspects of the current taxonomy, and nomenclatural changes are proposed. The first is the use of a rank free classification for the different Aplysia clades and subclades as opposed to previously used genus and subgenus affiliations. The second is the suggestion that Aplysia brasiliana Rang, 1828 is a junior synonym of Aplysia fasciata Poiret, 1789. The third is the elimination of Neaplysia since its only member is confirmed to be part of the large Varria clade.