Name in Smith, 1943 : Natrix trianguligera

Current Scientific Name :

Xenocrophis trianguligerus ( Boie, 1827 )

Common Name : Triangle-spotted Keelback

Xenocrophis trianguligerus ( Boie, 1827 )
Triangle-spotted Keelback

Material Examined : 9 adults.

Description & Scalation : Stout-bodied. Head slightly broader than neck. Eye with round pupil. Nostrils directed slightly upwards; internasals distinctly narrowed and truncated anteriorly, longer than the prefrontals; 1 loreal as long as high. 1 preocular extending upper surface of the head, not touching the frontal; 3 postoculars, upper largest; temporals 2+1 or 2+2. Scales in 19:19:17 rows, strongly keeled exept outer 2 rows which are smooth; supralabials 9 ( 4th to 6th in contact with the eye ); infralabials 8, first 4 touching the first pair of genials; ventrals 146-151; subcaudals 84-98, paired; anal divided.

Coloration : Juveniles are beautifully marked with red coloration on the sides of the body. Juveniles and adults have glossy scales. Adults show two color forms:

  1. Uniform blackish gray, with indistinct, uneven, oblique black cross bars on body and tail above, off-white or grayish below. Lip scales brownish-gray, with pale black or brown edges.
  2. Uniform dark black above, whitish below. Lip scales brown, with distinct black edges.

Natural History : Nocturnal in its habits. A semi-aquatic snake, found around fresh water bodies and paddy fields. Many individuals were sighted while catching frogs, on hill-top forest around small streams /water accumulated along road sides, also observed in lowland pandanus swamp, forested roads always close to water bodies. This species occurs in the same geographical areas, where Boiga wallachi ( Nicobar Cat Snake ) occurs. Mainly feeds on frogs, tadpoles and fish. Never tried to bite while handling. Lays about 5-15 eggs. Grows up to 1.2m.

Distribution - India : Southern Nicobar Group of Islands, common on Great Nicobar Island, uncommon on Little Nicobar Island. Elsewhere: Widespread in Southeast Asia.

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Visitors Since 15th June 2012.
Last Updated Date 13 August 2013.