Unfinished symphony: updating the systematics of Aeolidiidae (Nudibranchia, Gastropoda), with special focus on Aeolidiella Bergh, 1867

This paper updates the systematics of Aeolidiidae (Heterobranchia, Nudibranchia), with special emphasis on the genus Aeolidiella Bergh, 1867. Up to now, Aeolidiella was composed of five valid species: A. alderi, A. glauca, A. rubra, A. sanguinea from the Mediterranean Sea and the Eastern Atlantic and A. drusillacomb. nov. from the Pacific Ocean. To clarify the systematics of this genus we present an integrative approach based on molecular and morphological data, literature review, species delimitation approaches, and haplotype network analysis. Aeolidiella glauca was recognized as a species complex resulting in the description of Aeolidiella avatarsp. nov., whereas the nominal name A. rubra is considered nomem dubium. The species Aeolidiella drusillacomb. nov. is ascribed to the new genus Novaeolidiellagen. nov. together with the new species Novaeolidiella janaesp. nov. from the Philippines. This restricts the genus Aeolidiella to the Atlantic Ocean and Mediterranean Sea. ZooBank: urn:lsid:zoobank.org:pub:2A14F139-675B-4079-B908-B5EBA20F36E3