Phylogenetic Analyses Reveal a Unique Species of Elaphe (Serpentes, Colubridae) New to Science

The snakes comprising the monophyletic group referred to as ratsnakes are found throughout Asia, Europe and the New World. Recently, three snake samples likely belonging to the ratsnakes were collected in Zoige County, Sichuan Province, China. Species identity was difficult to delimit morphologically because the specimens were juveniles and partially damaged. Subsequently, a molecular phylogenetic approach was used. Portions of three mitochondrial genes (cyt b, ND4 and 12S rRNA) were sequenced and analyzed. The results showed that they were sister to the genus Elaphe. Very little genetic variation was found among the three samples. The minimum genetic distances between these samples and those within Elaphe were greater than any currently recognized species within the genus. We conclude that this likely represents a new species within the genus Elaphe. Adult specimens and a morphologic description are needed for further study.