Systematic revision of the gastropod family Philinidae (Mollusca: Cephalaspidea) in the north-east Atlantic Ocean with emphasis on the Scandinavian Peninsula

Abstract

The taxonomy of the family Philinidae has been hampered by a lack of proper species descriptions combining morphological, anatomical, and phylogenetic data within a comparative framework. To date, most descriptive work has been based on shells alone and on few specimens. We here followed an integrative taxonomic approach to study the diversity of the family in the north-east Atlantic, with emphasis on the Scandinavian Peninsula, by combining shell and morpho-anatomical characters with molecular phylogenetic inference. Synonyms, ecology, and geographical distributions are given for each species and a dichotomous key for species identification is provided. Anatomical dissections, examination of shells, radulae, gizzard plates, male reproductive systems, and molecular phylogenetics based on the mitochondrial cytochrome c subunit I (COI) were used to discriminate amongst species and define diagnostic characters. Nineteen species of Philinidae were recognized, including two new to science (Philine indistincta sp. nov. and Philine grandioculi sp. nov.). The presence of Philine quadripartita (and not Philine aperta) in the north-east Atlantic is confirmed. Species can be best differentiated by their external morphology, shells, and male reproductive system. The generic division of Philinidae into Johania, Laona, Philine, and Praephiline was not supported and all species have been ascribed to the genus Philine. © 2013 The Linnean Society of London