Let’s be honest, the tentacled snake (Erpeton tentaculatum) is not the flashiest reptile in the jungle. These snakes blend in with their native habitat of freshwater or brackish lakes, ditches, and other wetlands in Southeast Asia, thanks to mottled gray, brown, and green scales that line their bodies. They average a modest 50 centimeters in length – just a bit longer than your forearm. The tentacled snake’s coloration acts as camouflage, and the snake augments this disguise with its behavior. When disturbed, tentacled snakes straighten their bodies and become stiff, enhancing their stick-like appearance.
Photo by Jeremy P. [Source].
While their coloration favors subtlety over flair, tentacled snakes sport some interesting facial features. Two short, scaly “tentacles” – quite unlike the tentacles that other animals have (including octopus, jellyfish, and corals) – protrude from the snout. They look very similar to eye-stalks on a slug, or perhaps a sophisticated mustache. These appendages may be stylish, but they’re also functional, and give the snakes their namesnake.
Produced by Kenneth C. Catania [Source].
In accordance with their aforementioned inconspicuous coloration, tentacled snakes are skilled ambush predators, taking advantage of their preys’ natural escape responses [1]. When hunting, they strike a “J”-shaped pose and remain extremely still, until their tentacles sense the presence of a small fish or crab [2]. When an unlucky victim wanders close enough to the snake’s head that the vibrations from its swimming are picked up by the motion-sensing tentacles, the snake executes its strategy. First, it performs a “bump” of its body, sending vibrations of water towards the fish. The fish, startled by the sudden movement, instinctively executes an escape maneuver in the opposite direction. This is called a “C-start”, after the shape the fish’s body makes as it turns to swim away [3]. However, due to the snake’s “J” position, the fish’s escape attempt places it directly in front of the snake’s waiting jaws. The snake strikes, snagging the fish and injecting venom with its rear fangs, and the fish goes from enjoying its day to becoming dinner [2].
Photo by Ryan Somma [Source].
Tentacled snakes are viviparous, meaning they give birth to live young directly into the water, rather than laying eggs like most snakes [4]. These infant snakes are born knowing how to take advantage of the C-start behavior of fish, and don’t need to be taught by a parent in order to begin hunting [4].
Photo by Brittany Steff, Smithsonian’s National Zoo [Source]
Tentacled snakes are so at home in their aquatic habitats that they’ve adapted to remain underwater for up to 30 minutes without taking a breath [4]. When they do need to breathe, they will poke only their nostrils out of the water. Since they’re so adapted to aquatic life, tentacled snakes struggle to move effectively on land. During dry seasons, they will bury themselves in mud until the wet season returns [4].
Fortunately, these deceptive little mustachioed snakes are rated as Least Concern by the IUCN Red List, though there have not yet been any investigations into their population size or trends [5]. Tentacled snakes can be found in the wild in murky wetlands in Thailand, Cambodia, and Vietnam [1-3] as well as in captivity in zoos around the world [4].
Cover image: Tentacled Snake (2005) by Smithsonian Institution. Digitally enhanced by rawpixel [Source].
Written by: Izzy Kier is a 1st year PhD student in the Animal Behavior Graduate Group. She studies titi monkey pair bonding and how it relates to parenting and infant outcomes. She is interested in conservation work, both in the wild and in captive settings. In her free time, she enjoys hiking, camping, and reading. Originally from the East Coast, she loves exploring all that California has to offer.
References
[1] Catania, K. C. (2011). The brain and behavior of the tentacled snake. Annals of the New York Academy of Sciences, 1225(1), 83–89. https://doi.org/10.1111/j.1749-6632.2011.05959.x
[2] Tentacled Snake. (n.d.). Smithsonian’s National Zoo and Conservation Biology Institute. Retrieved May 5, 2024, from https://nationalzoo.si.edu/animals/tentacled-snake
[3] Catania, K. C. (2022). Tentacled snakes. Current Biology, 32(18), R939–R940. https://doi.org/10.1016/j.cub.2022.08.003
[4] New at the Zoo: Tentacled Snake Babies. (2018, March 2). Smithsonian’s National Zoo and Conservation Biology Institute. https://nationalzoo.si.edu/animals/news/new-zoo-tentacled-snake-babies
[5] Murphy, J., Brooks, S.E. & Bain, R.H. 2010. Erpeton tentaculatum. The IUCN Red List of Threatened Species 2010: e.T176697A7285596. https://dx.doi.org/10.2305/IUCN.UK.2010-4.RLTS.T176697A7285596.en. Accessed on 13 May 2024.
[Edited by Alice Michel & Jacob Johnson]
theethogram.com 
