Not so sluggish: the success of theFelimare pictacomplex (Gastropoda, Nudibranchia) crossing Atlantic biogeographic barriers

Abstract

The molecular phylogeny of the Atlanto-Mediterranean species of the genus Felimare, particularly those attributed to the speciesF. picta, was inferred using two mitochondrial markers (16S and COI). A recent revision of the Chromodorididae clarified the taxonomic relationships at the family level redefiningthe genusFelimare. However, conflicting taxonomic classifications have been proposed for a restrict group of taxa with overlapping morphological characteristics and geographical distributions designated here as theFelimare pictacomplex. Three major groups were identified: one Mediterranean and amphi-Atlantic group; a western Atlantic group and a tropical eastern Atlantic group.F. pictaforms a paraphyletic group since some subspecies are more closely related with taxa traditionaly classified as independent species (e.g.F. zebra) than with other subspecies with allopatric distributions (e.g.F. picta pictaandF. picta tema). Usually, nudibranchs have adhesive demersal eggs, short planktonic larval phases and low mobility as adults unless rafting on floating materials occurs. Surprisingly however, the phylogeny of theF. pictacomplex suggests that they successfully cross main Atlantic biogeographic barriers including the mid-Atlantic barrier. This ability to cross different biogeographic barriers may be related toF. picta’s distinct life history and ecological traits. Compared to other ChromodorididaeF. pictahas larger eggs and planktotrophic larvae which could be related to a longer planktonic phase.