Identification:
- Head elongated, distinct from the neck.
- Eyes small, with round pupils.
- Nostrils located between the nasal shields.
- Two internasal shields smaller than the prefrontal shields; frontal shield more than twice as long as wide, and longer than its distance to the snout tip; two large parietal shields.
- One temporal shield as wide as it is tall, one preocular shield tall, separated from the frontal shield by a supraocular shield.
- Three postocular scales, two subocular scales; the second subocular separates the eye from the 6th supralabial scale.
- Temporal scales 2+2, long and smooth.
- Mental scale triangular, its border shorter than the rostral scale.
- Two pairs of postmental scales, the first pair completely touching each other and shorter than the second pair.
- Nine supralabial scales, a portion of the 4th and 5th touching the eye, 10 infralabial scales, the first pair touching each other behind the mental scale, 5 touching the first postmental scale on each side.
- 19 rows of dorsal scales, keeled except for the two outermost rows, 137 ventral scales, 71 subcaudal scales. Anal plate divided.
Measurements:
- Body length: 558 mm
- Tail length: 210 mm
- SV = 9, IL = 10, C = 19, V = 137, SC = 71.
Coloration:
- Body grayish-brown, with transverse black markings on the back and sides, sometimes interspersed with faint reddish-brown streaks.
- The top of the head is darker, with two black stripes extending from the eyes to the 6th and 8th supralabial scales, and another black stripe extending from the posterior angle of the jaw to the nape.
- Belly opaque white, the anterior edges of the ventral scales often with black borders.
Biology and Ecology:
- Aquatic snake that preys on fish and rodents.
- Species lays many eggs: clutches of up to 100 eggs have been recorded, although the usual range is 17-52 eggs.
- Incubation period: 5 to 7 weeks.
- Hatchlings are 15 – 21cm in length.
- This common terrestrial snake is active day and night, inhabiting ponds, streams, rice paddies, and freshwater areas up to 1,600 meters in altitude.
Distribution:
- Vietnam: Widely distributed, found almost from North to South, and very common in the Mekong Delta.
- World: Thailand, Cambodia, Laos, China, Malaysia, India, Nepal.