Aeolidida is one of the largest clades of nudibranchs with at least 560 known species. However, its systematics has not been studied in a comprehensive manner. Phylogenetic analyses of larger clades such as Nudibranchia or Cladobranchia have usually included a poor sample of aeolids. Furthermore, phylogenetic studies at the family or generic level in Aeolidida are a few and far between. The first molecular phylogeny of the aeolid family Aeolidiidae is presented here. This study, the most comprehensive for Aeolidida to date, uses new sequences of two mitochondrial (COI and 16S) genes and one nuclear gene (H3). 251 specimens from members of seven families of Aeolidida, including 39 species of Aeolidiidae were studied. Excluding
Pleurolidia juliae, Aeolidiidae is monophyletic. Our results resolve the systematic relationships within the Aeolidiidae at a generic level, requiring changes in the systematics of this family.
Spurilla, Anteaeolidiella, Limenandra and
Aeolidia are well-supported and monophyletic clades.
Aeolidiella stephanieae is transferred to
Berghia and
Aeolidiopsis ransoni and
Spurilla salaamica to
Baeolidia, to maintain the monophyletic lineages reflected in this study. The systematics of
Cerberilla remains unclear. Some species earlier attributed to
Aeolidiella are now grouped in a previously unnamed clade that we designate as
Bulbaeolidia gen. nov.