Wednesday, January 31, 2024

[Herpetology • 2024] Bungarus sagittatus • A New Species of Krait of the Genus Bungarus (Serpentes: Elapidae) from Ratchaburi Province, western Thailand


Bungarus sagittatus 
Aksornneam, Rujirawan, Yodthong, Sung & Aowphol, 2024

Tenasserim Krait | งูทับสมิงคลาตะนาวศรี || DOI: 10.3897/zse.100.116601

Abstract
We described a new species of elapid snake genus Bungarus from the Tenasserim Mountain Range in Ratchaburi Province, western Thailand. Bungarus sagittatus sp. nov. can be distinguished from all congeners by having the combination of 15 dorsal scale rows; 215–217 ventral scales; 48–56 undivided subcaudal; prefrontal suture 2.4–2.6 times length of internasal suture; anterior chin shields larger than posterior chin shields; head of adult uniform black while juvenile black with small dim white patches on temporal and parietal areas; dorsal body black, with 25–31 white narrow bands, white and black bands at midbody covering 1.5–3.0 and 4.5–6.0 vertebral scales, respectively; dorsal body black bands not intruding ventrals or intruding ventrals less than 0.5 times of width of outer dorsal scales; ventral surface of body immaculate white; ventral side of tail white with a row of dark brown triangular patches on middle pointing posteriorly; tail relatively long, tail length/total length 0.140–0.143. Genetically, the new species has uncorrected pairwise divergences of ≥ 8.29% of the mitochondrial cytochrome b from other Bungarus species. Currently, the new species is only known from the type locality.

Key Words: biodiversity, snake, Southeast Asia, systematics, Tenasserim


Bungarus sagittatus sp. nov.
Paratypes in life showing the variation in different age class.
A. Subadult female (ZMKU R 01088); B. Juvenile (ZMKU R 01090).

Bungarus sagittatus sp. nov.

Diagnosis: Bungarus sagittatus sp. nov. is assigned to the genus Bungarus by its recovered phylogenetic position and having enlarged, hexagonal-shaped, midbody vertebrae scales (Smith 1943; Slowinski 1994). This species can be distinguished from other species of Bungarus by the following combination of characters: 15–15–15 dorsal scale rows; 215–217 ventral scales; 48–56 undivided subcaudal; prefrontal suture 2.4–2.6 times length of internasal suture; anterior chin shields larger than posterior chin shields; head of adult uniform black while juvenile black with small dim white patches on temporal and parietal areas; dorsal surface of body black, with 25–31 white narrow bands, white and black bands at midbody covering 1.5–3.0 and 4.5–6.0 vertebral scales, respectively; dorsal black bands of body not intruding ventrals or intruding ventrals less than 0.5 times of width of outer dorsal scales; ventral surface immaculate white; ventral side of tail white with a row of dark brown triangular patches on middle pointing posteriorly; tail relatively long, tail length/total length = 0.140–0.143.


Etymology: The specific epithet sagittatus is derived from sagittata (L.) meaning arrow and in reference to the dark triangular shape on subcaudals which resembles a barbed arrow.

Distribution: Bungarus sagittatus sp. nov. is currently known from type locality: Khao Krachom, Suan Phueng District, Ratchaburi Province. The area is part of Tenasserim Mountain Range, which lies on Thai-Myanmar borderline.


Akrachai Aksornneam, Attapol Rujirawan, Siriporn Yodthong, Yik-Hei Sung and Anchalee Aowphol. 2024. A New Species of Krait of the Genus Bungarus (Squamata, Elapidae) from Ratchaburi Province, western Thailand. Zoosystematics and Evolution. 100(1): 141-154. DOI: 10.3897/zse.100.116601