An investigation into the taxonomy of Dendrelaphis tristis (Daudin, 1803): revalidation of Dipsas schokari (Kuhl, 1820) (Serpentes, Colubridae)

Abstract

The taxonomic status of the colubrid snake Dendrelaphis tristis (Daudin, 1803) was investigated on the basis of morphological data taken from 64 museum specimens. Univariate and multivariate analyses of these data reveal that Dendrelaphis tristis is composed of two species. One of these species agrees with the description of Dipsas schokari Kuhl, 1820 which is revalidated in the combination Dendrelaphis schokari (Kuhl, 1820). The syntypes of D. schokari have been lost and a type for D. tristis has never been deposited in a collection. Neotypes are designated and described for both species in order to stabilize the names. D. schokari differs from D. tristis in having a lower number of ventrals and subcaudals, a larger eye, a shorter vertebral stripe and the absence of a bright interparietal spot. D. tristisand D. schokari exhibit a partially overlapping distribution. D. tristis ranges from Sri Lanka northward through most of India to Myanmar whereas the distribution of D. schokari is restricted to Sri Lanka and South-west India (Western Ghats). Although the two species coexist on Sri Lanka and in South-west India, these species presumably do not occur syntopically as suggested by their distribution patterns and morphology.

Nominal taxa of Spalerosophis diadema (Schlegel, 1837) from Iraq to Pakistan — two centuries of confusion (Reptilia: Squamata: Colubrinae)

“…This recently resulted in the désignation of a neotype for Coluber tristis Daudin. 1803a by Rooijen & Vogel (2008) who believed Russell's spécimens to be stored in Paris (MNHN), the working place of François Marie Daudin ("Daudin did not deposit a type-specimen in a collection as was usual at that time").…”

FIRST CONFIRMED DISTRIBUTION RECORDS OF Dendrelaphis bifrenalis (BOULENGER, 1890) (REPTILIA: COLUBRIDAE) IN INDIA, WITH A REVISED KEY TO THE SOUTHERN INDIAN FORMS

“…Of these, only the commonest, D. tristis (Daudin, 1803), is widespread (Das 2002, Whitaker & Captain 2004. Four more species are endemic to the wet zones of southwestern India, in the Western Ghats, namely: D. chairecacos (Boie, 1827), D. grandoculis (Boulenger, 1890), D. ashoki and D. girii (see van Rooijen & Vogel, 2008, 2009Vogel & van Rooijen, 2011a,b). While D. tristis, D. schokari (endemic to Sri Lanka) and D. chairecacos belong to the D. tristis group, D. grandoculis plus D. caudolineolatus and D. effrenis (both Sri Lankan) belong to one (phenetic) group (Wickramasinghe 2016, Danushka et al 2020.…”

A New Species Of <i>Dendrelaphis</i> (Serpentes: Colubridae) From The Western Ghats - India

“…Pethiyagoda, 2005;Wickramasinghe et al, 2007;Mukherjee & Bhupathy, 2007). This notion is underscored by recent insights into the taxonomy of the genus Dendrelaphis: one Sri Lankan endemic, D. schokari Kuhl, 1820 was resurrected from synonymy (Van Rooijen & Vogel, 2008), one South Indian species, D. chairecacos Boie, 1827, was resurrected from synonymy (Van Rooijen & Vogel, 2009), and two new species, D. ashoki Vogel & Van Rooijen, 2011a and D. girii sp. nov. (this report) have now been described from the Western Ghats.…”

“…Recent species descriptions and revalidations suggest that levels of endemism harboured by Sri Lanka as well as the Western Ghats may be substantially higher than currently known (e.g. Mukherjee & Bhupathy, 2007;Van Rooijen & Vogel, 2008;2009;Vogel & Van Rooijen, 2011a). This notion, as well as some observed differences in coloration between the Sri Lankan and Indian sister populations of Dendrelaphis bifrenalis, incited this study into the population systematics of this species.…”