[8] F. asperrima is found in Sri Lanka,[8][9][10] in both dry and wet climatic zones up to 1,000 m (3,300 ft) above mean sea level.

It is abundant in waterways, such as flooded rice fields, ponds, lakes, marshes, rivers and streams.

[2][6][11] The body of F. asperrima is short and cylindrical, and has a clear neck and slightly pointed head.

The eyes have rounded pupils, and the nostrils are narrow, directed slightly upwards.

The anterior half of the body has 20–32 distinct large black spots or cross bars.

It is active in water bodies in search of its prey, which consist mainly of fishes and frogs.