Caecidae is a species-rich family of microsnails with a worldwide distribution. Typical for many groups of gastropods, caecid taxonomy is largely based on overt shell characters. However, identification of species using shell characteristics is problematic due to their rather uniform, tubular shells, the presence of different growth stages, and a putative high degree of intraspecific variability. In the present study, we provide a first integrative approach to caecid taxonomy using light-microscopic investigation with microsculptural analyses and multi-marker barcoding, in conjunction with molecular species delineation analyses. We analyze 132 specimens of Caecum and Meioceras collected during several sampling trips to Central America. This first integrative approach towards the taxonomy of Caecidae increases the known diversity, reveals the need for a reclassification of the genus Caecum and serves as a starting point for a barcoding library of the family, thereby enabling further reliable identifications of these taxonomically challenging microsnails in future studies.
Keywords: DNA taxonomy, marine biodiversity, meiofauna, molecular species delineation, Mollusca