Snails in depth: integrative taxonomy of Famelica, Glaciotomella and Rimosodaphnella (Conoidea: Raphitomidae) from the deep sea of temperate Australia

Abstract

The deep sea of temperate south-eastern Australia appears to be a ‘hotspot’ for diversity and endemism of conoidean neogastropods of the family Raphitomidae. Following a series of expeditions in the region, a considerable amount of relevant DNA-suitable material has become available. A molecular phylogeny based on this material has facilitated the identification of diagnostic morphological characters, allowing the circumscription of monophyletic genera and the introduction of several new genus-level taxa. Both named and new genera are presently being investigated through integrative taxonomy, with the discovery of a significant number of undescribed species. As part of this ongoing investigation, our study focuses on the genera Famelica Bouchet & Warén, 1980, Glaciotomella Criscione, Hallan, Fedosov & Puillandre, 2020 and Rimosodaphnella Cossmann, 1914. We subjected a comprehensive mitochondrial DNA dataset of representative deep-sea raphitomids to the species delimitation methods ABGD and ASAP that recognised 18 and 15 primary species hypotheses (PSHs) respectively. Following additional evaluation of shell and radular features, and examination of geographic and bathymetric ranges, nine of these PSHs were converted to secondary species hypotheses (SSHs). Four SSHs (two in Famelica and two in Rimosodaphnella) were recognised as new, and formal descriptions are provided herein.