English name: Tentacled Snake (aka: “Tentacle Snake”, “Fishing Snake”)
Scientific name: Erpeton tentaculatum
Thai name: Ngu Kra Daen
Description: To 90cm long. Body is slender and flattened. Head is trapezoid-shaped. Has two short “tentacles” that protrude from either side of its snout. Tail is prehensile. Body color can be gray to brown, with different color phases including widely separated short dark bands, much broader dark bands with little separation, or longitudinal stripes. Head has a reddish-brown stripe on each side that runs from the appendage to the eye. Venter is yellowish-brown.
Similar Species: The Tentacled Snake is the only snake in the world with a pair of protruding appendages on its snout. It is also more slender and flattened than the other water snakes in our area.
Habitat: Found in stagnant lakes, streams, and rice paddies, in areas with murky water and vegetation. Can live in fresh, brackish, or sea water. May burrow into mud during dry periods, but otherwise is not found on land.
Contribution to the ecosystem: Helps keep fish populations in balance. Occasionally feeds on shrimp. Provides food for larger snakes, large fish, monitors, and wading birds.
Danger to humans: Rarely bites. Is a rear-fanged snake, but it has a weak, fish-specific venom and is of no danger to humans.
Conservation status and threats: The Tentacled Snake is common in its range, though there is some harvest for its meat. Like other water snakes it potentially faces declines in the Tonle Sap Lake due to the extensive snake harvest there.
Interesting facts: The Tentacled Snake has one of the most fascinating hunting techniques in the snake world. It ambushes its prey by waiting in a “J” position, with its tail anchoring its body to vegetation and its head curved back towards its body. When a fish swims nearby, the appendages on the snake’s head sense the fish’s movements via disturbances in the water. Once the fish gets close the snake moves part of its body behind the neck, creating a reflex movement in the fish. The snake immediately strikes with its head exactly where it anticipates the fish’s reflex movement to direct it. This is the only snake that is known to induce a flight response in its prey and strike where it anticipates the prey to be going, rather than aiming at its current location. Watch these videos to see the Tentacled Snake in action.
Wikipedia: Erpeton tentaculatum
IUCN Redlist: Erpeton tentaculatum
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
A Field Guide to the Snakes of South Vietnam
Snakes of Thailand and their Husbandry
Simon & Schuster’s Guide to Reptiles and Amphibians of the World