A DNA-barcoding approach to the phenotypic diversity of Mediterranean species of Felimare Ev. Marcus & Er. Marcus, 1967 (Mollusca: Gastropoda), with a preliminary phylogenetic analysis

Abstract The chromodorid nudibranchs Felimare tricolor (Cantraine, 1835), F. fontandraui (Pruvot-Fol, 1951) and F. picta (Shultz in Philippi, 1836) typically show highly variable colour patterns that are misleading for species identification. Their taxonomy has long been confused, and their identification can be difficult if based only on morphological characters. We carried out molecular genetic analyses using the mitochondrial cytochrome c oxidase subunit I (COI) and 16S rDNA markers on Mediterranean samples of these three taxa representing a large part of their range of chromatic variation. Results proved the usefulness of the DNA-barcoding approach in assessing species delimitation in this group, and in identification of specimens with body colours not clear for species recognition. We inferred preliminary phylogenetic relationships among one third of the currently recognised species of Felimare: they indicated with good support sister species relationship among Felimare tricolor and F. fontandraui, and suggested (with low support) potential relationships among F. picta, F. verdensis, F. californiensis and F. agassizi.