On the validity of Hebius sauteri maximus (Squamata, Natricidae), with redescription of H. maximus comb. nov. and H. sauteri from China

Hebius sauteri (Boulenger, 1909) has been long recognized as a widely distributed species with three subspecies, namely Hebius sauteri sauteri from Taiwan Island and southeastern China, Hebius sauteri bourreti (Malnate, 1962) from northern Vietnam, and Hebius sauteri maximus (Malnate, 1962) from Sichuan, southwestern China. However, the validity of these subspecies partition of H. sauteri complex has not been evaluated. In the current study, we re-evaluate the taxonomic status of H. s. maximus based on morphological and molecular evidence. Molecular phylogenetic results indicate that H. s. maximus is a distantly diverged clade with respect to H. s. sauteri , and H. s. maximus is morphologically distinguishable from the latter nominate subspecies. Therefore, we support the validity of H. s. maximus and elevate it to full species status, namely Hebius maximus comb. nov. , and we revise the distribution range of H. sauteri according to our proposed taxonomic change. Furthermore, detailed redescription, natural history, and coloration of both H. sauteri and H. maximus and comments on the validity of H. s. bourreti are also provided.