Image credit: Ryan Somma/Flickr
Erpeton tentaculatum is the only known snake with tentacles and new research has explained what purpose the unique appendages serve.
The snake is found in rivers and lakes in South-East Asia. The aquatic habitat is often murky and, researchers believe, the snake's tentacles help it "see" in low-visibility environments.
Initially, researchers thought that the tentacles were used to detect fish, which the snake eats almost exclusively. However, under close observation, they found that nerve fibers in the tentacles were bundled near the center, not close to the outside. This implies that the tentacles detect motion and movement, not taste as smell as researchers first thought.
The snake responded immediately when the tentacles were stimulated. By monitoring electrical activity in the snake's brain, researchers found that sensations felt by the tentacles activated the area of the brain devoted to sight. The snakes, it seemed, were using the two different sources of information together.
E. tentaculatum curls its body into the shape of a J, tricking fish into swimming towards its mouth instead of towards safety. When tested in various light conditions, the snake was able to capture fish whether the prey was visible or not.
The conclusion, researchers explained, is that the snake's tentacles support its eyes, contributing important information when visibility is low—like in murky water or at night.