English name: Javan Wart Snake (aka: “Elephant Trunk Snake” or “Javan File Snake”)
Scientific name: Acrochordus javanicus
Thai name: Ngu Nguang-chang
Description: To 290cm long. Thick body and loose folds of skin lead to the common name “Elephant Trunk Snake”. Skin is covered with small pyramid-like scales that are rough to the touch, giving the alternative common name “file snake”. Head is flat and wide with the nostrils and eyes positioned on top. Tail is round. Body is olive-brown to grayish-black on top, fading to pale yellow on the sides and belly. There are diffuse longitudinal dark lines and blotches on the flanks and dark lines on the head.
Similar Species: Little File Snake is smaller and has transverse cream bands rather than indistinct longitudinal dark lines/blotches.
Sea Snakes of the Elapidae family have a paddle-shaped tail.
Habitat: The Javan Wart Snake is occasionally found in the ocean, but prefers the brackish or fresh water of slow-moving rivers and streams in coastal areas. It is able to live in ditches and canals of degraded agricultural habitats. It becomes almost entirely aquatic as it matures and has difficulty moving on land as an adult. Usually hides in the roots of trees lining the water during the day, coming out into open water at night to hunt.
Contribution to the ecosystem: The Javan Wart Snake helps to control fish populations. Frogs are also included in its diet. Smaller juveniles provide food for large fish, monitors and wading birds.
Danger to humans: Has no venom, rarely bites and is not dangerous to humans, though it can deliver a painful bite if it chooses to do so.
Conservation status and threats: The Javan Wart Snake is currently common and populations appear able to withstand a great deal of hunting pressure and habitat degradation. Still, there are concerns as hundreds of thousands are killed each year for their skins, which are turned into leather after the scales are removed. Their flesh is also sold in markets and eaten.
Interesting facts: The Javan Wart Snake feeds on fish, which it surprises by ambushing at the bottom of the water bodies where it lives. When it grabs a fish it grips it with the coils of its body, which are able to hold onto the slippery fish due to their rough, triangular scales.
Female Javan Wart Snakes can be more than 50% longer and much thicker than the males, an unusual extreme in sexual dimorphism among snakes.
IUCN Redlist: Acrochordus javanicus
Thailand Office of Environmental Planning and Policy: A Checklist of Amphibians and Reptiles in Thailand
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Reptiles of South-East Asia
Guide to the Snakes of South Vietnam
Snakes of Thailand and their Husbandry