Bungarus andamanensis explained

Bungarus andamanensis, the South Andaman krait, is a species of krait, a venomous elapid snake, which is found in the Andaman Islands of India. It was first described by Biswas and Sanyal in 1978.

Description

The Andaman Krait is a medium-sized snake, growing up to 1.3 meters in length. Its body is cylindrical, and the head is slightly broader than the neck. The eyes are small and entirely black with round pupils.

Scalation

• Dorsal scales: Smooth, arranged in 15:15:15 rows, with vertebral scales strongly enlarged.
• Head scales: Internasals shorter than prefrontal scales. No loreal scale; the preocular scale contacts the posterior nasal. Two postocular scales, with temporal scales arranged in 1+2 configuration.
• Labial scales: 7 supralabials (the 3rd and 4th touch the eye; the 6th is the largest) and 7 infralabials (the first 3 contact the genials).
• Ventrals and subcaudals: 192–200 ventral scales and 40–47 entire subcaudal scales. The tail ends with a thick blunt point, and the anal plate is entire.

Coloration

The body is glossy black or brownish, often with blue iridescence. It features 39–47 narrow yellow or white equidistant cross-bars on the body and 9–13 on the tail, with the bands widening toward the belly. The underside is yellowish-cream with irregular black or brown spots, and the tail often has distinct brownish spots. The lips are yellowish. Juveniles display vibrant yellow cross-bars and a distinct "^"-shaped marking near the head.

Distribution and Habitat

The Andaman Krait is endemic to the Andaman Islands and Little Andaman Islands in India. It inhabits a variety of environments, including:

• Paddy fields
• Low bushes on mountains and coastal areas
• Mangroves
• Freshwater streams

The species is frequently observed on roads after rains and has also been seen near termite mounds. It is extremely common in Little Andaman.

Ecology

Behavior

The Andaman Krait is nocturnal and primarily active during and after rains. When alarmed, it slightly flattens its body, coils loosely while hiding its head, and may produce a squeaking sound. Juveniles are most often seen in June, suggesting a seasonal breeding pattern.

Diet

The species mainly preys on other snakes, including water snakes, and occasionally on fish. Adult specimens are rare and are typically found near freshwater streams.

Reproduction

Little is known about the breeding biology of this species, but the presence of juveniles in June indicates potential seasonal reproduction.

References

• Biswas S; Sanyal D P 1978 A new species of krait of the genus Bungarus Daudin, 1803 (Serpentes: Elapidae) from the Andaman Island. J. Bombay Nat. Hist. Soc. 75 (1): 179-183
• Das, I. 1999. Biogeography of the amphibians and reptiles of the Andaman and Nicobar Islands, India. In: Ota. H (Editor), Tropical Island Herpetofauna: Origin, Current Diversity, and Conservation. Elsevier Science, Amsterdam, Holland. 43-77
• Harikrishnan, S., Vasudevan, K., & Choudhury, B. C. (2010). A review of herpetofaunal species descriptions and studies from Andaman and Nicobar Islands, with an updated checklist. In Ramakrishna, Raghunathan, C. and Sivaperuman, C. (Eds) 2010. Recent Trends in Biodiversity of Andaman and Nicobar Islands: 1-542 (Published by the Director, Zool. Surv. India, Kolkata)
• Slowinski J B. 1994 A phylogenetic analysis of Bungarus (Elapidae) based on morphological characters. Journal of Herpetology 28 (4): 440–446.