Brief SummaryRead full entry
The Asian keelback snakes (genus Amphiesma) are a widely distributed group of Old World natricine colubrid snakes, including at least 42 species (Guo et al. 2014 and references therein). These snakes, many of which are rare, have secretive habits and are poorly known. They inhabit a range of ecological niches and exhibit considerable morphological variation. Recent molecular phylogenetic analyses suggest that Amphiesma sensu lato is not monophyletic and that additional, still unrecognized cryptic diversity is likely present. Phylogenetic analyses using a combination of nuclear and mitochondrial markers indicate the existence of three distinct monophyletic lineages with strong support (Guo et al. 2014). Based on their analyses, Guo et al. divide Amphiesma sensu lato into three genera: Amphiesma, Hebius, and Herpetoreas. The genus Amphiesma as treated by Guo et al. (2014) is monotypic (including only A. stolatus); Herpetoreas includes three species; and Hebius includes 39 species. Based on a combination of molecular analyses and comparisons of external morphological characters, Guo et al. (2014) described a new species in the Herpetoreas group from China as H. burbrinki sp. nov. Several other species were shown to be non-monophyletic or to contain significant intraspecific genetic diversity.
Guo et al. suggest that further taxonomic revisions are needed in Natricinae, at multiple levels, and that this work should include studies focused on resolving the genus-level taxonomy of Amphiesma sensu stricto and the related genera Atretium, Rhabdophis, and Xenochrophis (at least the last of which is also apparently not monophyletic) as well as on clarifying species boundaries and geographic distributions within these groups.
(Guo et al. 2014 and references therein)