TAXONOMIC COMPOSITION OF THE Rhabdophis subminiatus (SCHLEGEL, 1837) SPECIES COMPLEX (REPTILIA: NATRICIDAE) WITH THE DESCRIPTION OF A NEW SPECIES FROM CHINA

Abstract

The systematics of Rhabdophis subminiatus (Schlegel, 1837) at subspecies level has long proved to be controversial. We analyse the variation of selected morphological characters in 179 specimens from populations covering the whole range of R. subminiatus sensu lato. Based on this review, we recognize four morphological groups, of which two do not agree with the current definitions and distributions of the currently recognized subspecies R. s. subminiatus. The ―northernmost group‖ agrees with the definition of Natrix helleri Schmidt, 1925. In contrast, the ―southernmost group‖ agrees with the syntypes of Tropidonotus subminiatus and we here restrict this species to the Sunda Region. We also discuss a previous designation of the lectotype of T. subminiatus, which we consider invalid, and we here make it valid in the sense of the Code. Furthermore, our analysis allows us to define a third group that is widespread in the Indochinese Region and Malayan Peninsula. For this geographically ―central group‖, the name Natrix subminiata siamensis Mell, 1931, is available. We therefore resurrect this taxon from its synonymy with R. subminiatus and we designate a lectotype in agreement with requirements of the Code. Lastly, we recognize a fourth group at species level, endemic to Hainan Island, China, that we describe as a new species. This division into four morphological groups at species level is coherent with phylogenetic analyses recently published in the literature. We also discuss and modify the taxonomic status of Natrix subminiata hongkongensis Mell, 1931 and Natrix (Rhabdophis) laobaoensis Bourret, 1934, now regarded as synonyms of R. subminiatus and R. siamensis, respectively.