The magic 'eyes' of water snakes

The miraculous tentacles of the water snake can help it 'see' prey in murky waters, due to the slight fluctuation of the water flow caused by the prey.

Erpeton Tentaculatum snake is used for experiment.

Ken Catania and colleagues at Vanderbilt University, Tennessee, used a light touch on the tentacles in Erpeton Tentaculatum's upper lip and recorded the results of their nerves. These tentacles are proving to be an extremely sensitive tactile part even with the slightest fluctuations.

The map of the tentacles' nerve pathways shows that the signal is directed into an area of ​​the brain (where sensory signals are produced) and there is a strong reaction to the signals visual effect. Catania explains: 'This shows that two parts of the information are exchanging and agreeing with each other'.

To test the ability to use the senses (tentacles and sight) to prey on this snake, researchers put them in a tank with defined water levels and next to their tanks to project a film. animation of swimming fishes. This snake has attacked the fish correctly, which suggests they can hunt only by using eyesight.

The researchers then put 5 live fish into a dark tank, and used the infrared camera to return. The results are: even though the snakes attack less, they can still attack and catch fishes swimming a few centimeters away from their heads and tentacles.

Catania claims that it is the tentacles that help the snake to hunt in the night and in the dark waters.