Sunday, November 29, 2020

[Herpetology • 2020] Rhinophis karinthandani • A New Indian Species of Rhinophis Hemprich, 1820 closely related to R. sanguineus Beddome, 1863 (Serpentes: Uropeltidae) from the Western Ghats of peninsular India


 Rhinophis karinthandani
Sampaio, Narayanan, Cyriac, Venu & Gower, 2020


Abstract
A new species of the uropeltid (shieldtail snake) genus Rhinophis is described based on a type series of seven specimens from the Wayanad region of the Western Ghats of peninsular India. The holotype was collected before 1880 but had been misidentified as the phenotypically similar and parapatric (possibly partly sympatric) R. sanguineus. Rhinophis karinthandani sp. nov. is diagnosed by a combination of 15 dorsal scale rows at midbody, 4–8 pairs of subcaudal scales, colour pattern (uniformly dark above, whitish below with extensive dark mottling), and by its distinct mitochondrial DNA sequences (e.g. >7.6% uncorrected p-distance for nd4). Phylogenetic analysis of mitochondrial DNA sequence data indicates that the new species is most closely related to R. sanguineus among currently recognised species, with this pair most closely related to the partly sympatric R. melanoleucus. The new species description brings the number of currently recognised species in the genus to 24, six of which are endemic to India and 18 endemic to Sri Lanka. A new key to the identification of Indian species of Rhinophis is provided.

Keywords: identification key, Rhinophis microlepis, shieldtail, snakes, Wayanad, Western Ghats, Reptilia


 Photographs of live Rhinophis karinthandani sp. nov. (A–D) and R. sanguineus (E–F).
A, B. dorsal and ventral views of BNHS 3541;
C, D. dorsal and ventral views of BNHS 3542;
E, F. dorsal and ventral views of VPRS0918093.

 Rhinophis karinthandani sp. nov.
 
 Chresonymy: Rhinophis sanguineus Beddome, 1863: 
Cyriac et al. 2020, in part (see Appendix 1)

Diagnosis. Rhinophis karinthandani sp. nov. differs from all other species of Rhinophis except R. fergusonianus Boulenger, 1896, R. melanoleucus, and R. sanguineus in having 15 dorsal scale rows at (or just behind) midbody (versus 17 or 19 in other congeners). Rhinophis karinthandani sp. nov. differs from R. fergusonianus and R. melanoleucus in having a reduction from 17 to 15 dorsal scale rows that occurs anterior to the 80th ventral (versus posterior to the 90th ventral in R. fergusonianus and posterior to the 99th ventral in R. melanoleucus: Cyriac et al. 2020), and in having dark spots or speckles ventrally (versus dark blotches). Rhinophis karinthandani sp. nov. differs from R. melanoleucus also in having fewer ventrals (< 206 versus > 217) and fewer subcaudals (in males: 4–5 versus 6–7). The new species is most similar superficially to the parapatric (possibly partly sympatric) R. sanguineus, but the two species can be distinguished on the basis of the former having fewer subcaudals (left-right means of 4–5 in females and 6.5–8 in males versus 5–7 and 8.5–10.5, respectively), having a reduction from 19 to 17 dorsal scale rows that occurs anterior to the 34th ventral (mean 28th ventral [n = 18 sides]; versus posterior to the 26th ventral, mean 34 [n = 28]) and a reduction from 17 to 15 dorsal scale rows that occurs anteriorly to the 78th ventral (mean 68th ventral [n = 18 sides]; versus posterior to the 67th ventral, mean 79th [n = 28]) (Appendix 4; Cyriac et al. 2020), in mitochondrial DNA sequences (e.g. >7.6% uncorrected p-distance for nd4: Table 1), and in colour pattern. In terms of colour pattern, both species have a dark dorsum and generally pale venter, but R. karinthandani sp. nov. has an extensively darkly mottled or speckled or spotted venter, except for a narrow (approximately one scale wide, generally across second and third and/or third and fourth dorsal scale rows), longitudinal, ventrolateral pale line along each side, immediately below the dark dorsum (and sometimes other, subparallel pale lines further ventrally), whereas R. sanguineus has a less mottled venter with the paler colour below the darker dorsum being much more extensive than a narrow regular line. In life, the paler venter of R. karinthandani sp. nov. is whitish (to pale pinkish more anteriorly), but in R. sanguineus is a vivid red (paler in smaller specimens, see Discussion). The colour pattern differences in preservation hold well for almost all specimens we have identified, although in R. sanguineus specimen VPRS0918093, many of the mostly pale scales in the broad pale areas below the darker dorsum have small blackish dots. At least in life, the dorsal colour of R. sanguineus appears to be darker, more blackish than in R. karinthandani sp. nov. Photographs of the type specimens of R. sanguineus and its junior synonym R. microlepis are presented in Figs. 4 and 5.

BNHS paratypes of Rhinophis karinthandani sp. nov. Heads and tails shown in (from left to right) dorsal, ventral, right lateral and left lateral views.
A. BNHS 3540; B. BNHS 3542; C. BNHS 3544; D. BNHS 3545; E. BNHS 3546.
Scale bars 10 mm.

Etymology. The species is named in honour of Karinthandan, a member of the Paniya (also Paniyar, Paniyan) tribe indigenous primarily to the tri-state region of Kerala-Karnataka-Tamil Nadu. Karinthandan is believed to have been a chieftain (= moopan) who was murdered in the 1700s by colonial British after he showed them the Thamarassery churam mountain pass between the Adivaram (foothills) and Wayanad plateau. Legend has it that Karinthandan’s spirit is today chained to a banyan tree at Lakkidi (a paratype locality of the new species), which has become a place of worship. In addition, Karinthandan in Malayalam is from “kari” meaning black and “thandan” (thandu) meaning stem or backbone, which also seems appropriate given the blackish dorsal colour of the newly described species. For nomenclatural purposes, the species epithet is considered a noun in apposition. 

 
 Filipa L. Sampaio, Surya Narayanan, Vivek P. Cyriac, Govindappa Venu and David J. Gower. 2020. A New Indian Species of Rhinophis Hemprich, 1820 closely related to R. sanguineus Beddome, 1863 (Serpentes: Uropeltidae). Zootaxa. 4881(1); 1–24. DOI: 10.11646/zootaxa.4881.1.1