A new species of Bythinella Moquin-Tandon, 1856 (Gastropoda: Caenogastropoda: Bythinellidae) from south-western France

The spring-snail genus Bythinella is a diverse group of minute operculate gastropods, usually restricted to springs and widely distributed in Europe. Species are primarily delineated based on shell characters such as size or overall shape. Nevertheless, studies molecular morphological approaches show that these can be highly variable do not necessarily have taxonomic significance. In this paper we formally describe name, according the requirements International Code Zoological Nomenclature, species identified by previously published phylogenetic analyses barcoding gap approach mitochondrial COI gene. results suggest micro-endemic currently recognized only from south-western France at its type locality. We also highlight barcode considerably reduces number valid region, strictly shell-based taxonomy probably overestimates richness Bythinella.