Boulenger's Keelback

Boulenger's keelback, also called the Sri Lankan keelback, is a water snake endemic to Sri Lanka, named for the herpetologist George Albert Boulenger. It occurs in both the dry and wet zones up to 1,000 m and is abundant in waterways such as flooded rice fields, ponds, lakes, marshes, rivers and streams. The body is short and cylindrical with a clear neck and slightly pointed head, and the tail is long (Wikipedia, general species account).

Hatchlings are about 10 cm long and adults reach 40 to 70 cm, the female being longer. The back is olive brown, and the front half of the body carries 20 to 32 large black spots or cross bars. Two black lines run diagonally from behind the eyes to the corners of the mouth, and the belly is white. Nationally Least Concern (Sri Lanka National Red List 2012, listed as Xenochrophis asperrimus).