Acrochordus granulatus

Jordan de Jong little file snake Acrochordus granulatus งูผาขี้ริ้ว Ngu Pa-ki-reu
Little File Snake beached in Australia (© Jordan de Jong)

English name: Little File Snake (aka: “Little Wart Snake”, “Marine File Snake”, “Banded File Snake”)
Scientific name: Acrochordus granulatus
Thai name: งูผาขี้ริ้ว (Ngu Pa-ki-reu)

Description: To 125cm long. Females are stout, while males are comparatively slender. Skin hangs loosely on the body and is covered with small pyramid-like scales that are rough to the touch, giving it the common name “file snake” or the alternative name “wart snake”. Head is flat and wide with the nostrils and eyes positioned on top. Tail is round and prehensile. Body is olive, blue, brown or black with white to beige bands.

Similar Species: Javan Wart Snake is larger and has broken-up dark lines/blotches rather than transverse light bands.
Keel-bellied Water Snake is more slender, lacks the loose skin, and has a clear white belly.
Banded Krait has a triangle-shaped body and lacks the loose skin.
Sea Snakes of the Elapidae family have a paddle-shaped tail.

Habitat: The Little File Snake is found in the ocean as well as in estuaries, swamps, ponds, and rivers in coastal areas. It is almost entirely aquatic and can be found up to 10 km offshore in waters as deep as 20 meters. During the day it buries itself under cover below the water, coming to the surface occasionally to breathe.

Place in the ecosystem: The Little File Snake feeds on fish. Smaller juveniles are eaten by monitors, large fish, and wading birds.

Danger to humans: Has no venom, is usually passive and is not dangerous to humans. However, it can easily be confused with sea snakes, which pack a deadly bite, so exercise caution before handling.

Conservation status and threats: Is common and widespread. Some are collected for the pet trade, for food, or for their skins, but this does not appear to be a threat to their populations. Many are killed accidentally by netting operations in shallow ocean water, but at this point the incidental take appears to be sustainable.

Interesting facts: The Little File Snake contains more blood in its body than similarly-size land snakes, with a much higher concentration of red blood cells. This allows it to stay underwater up to 139 minutes at a time, allowing it to wait patiently for the fish that form its diet.

The male snakes of this species are skinnier and longer than the females, and tend to hunt their prey more actively.

References:
IUCN Redlist: Acrochordus granulatus
Wikipedia: Acrochordus granulatus
Wild Singapore: Banded File Snake
Blood oxygen stores in the File Snake, Acrochordus granulatus, and in other marine snakes
Sexual Size Dimorphism and Reproductive Cycle of the Little File Snake Acrochordus granulatus in Phangnga Bay, 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
A Field Guide to the Snakes of South Vietnam
Snakes of Thailand and their Husbandry
Graeme Gow’s Complete Guide to Australian Snakes