Strange hunting method of snake water

Forget the stories about snakes hypnotizing their prey. The tentacled snake from Southeast Asia has developed a much more effective skill. The small water snake has found a way to move prey to make it move towards the snake's head to escape. In addition, the prey's reaction is so predictable that the snake directs its bite to the prey of the prey instead of following its movement.

Kenneth Catania, professor of biological sciences at Vanderbilt University, who used high-speed video to recreate this snake's special hunting technique, said: 'I have not found any reports about Other predators show the ability to act and predict prey behavior like this snake. '

His observations were published in the April 15 issue of Proceedings of the National Academy of Sciences. Cantania, the recipient of the MacArthur 'genius' award, studied the brain and behavior of animals with specialization. very high. He was fascinated by this tentacled snake because it was the only snake equipped with a pair of short tentacles on his nose, and he was curious about their function.

Cantania explained: 'Before I started studying a new animal, I often spent a while looking at their basic behavior'. The snake forms an unusual 'J' shape with its head at the bottom of the 'J' when it hunts. It then remains in place, not moving until a fish swims into the area near the hook of the 'J'. That's when the snake attacks.

The movement of this snake takes only a few percent of a second and is too fast for the human eye to keep up. However, its prey reacts even faster, only a few thousandths of a second. In fact, fish are very famous for their ability to escape very quickly and this is a widely studied topic. These studies found that many fish species have a special nerve pathway in the brain that triggers a runaway, biologists call it 'C-activation'. Fish ears feel sound pressure on both sides of the body. When the ear on one side noticed the disturbance, it sent a message to the muscles that made the body curve into a C-shape and headed to the opposite side so that it could escape from danger most quickly.

The chart illustrates how snakes have to use a part of the body to stimulate the C's boot of the fish and make them swim straight towards the snake's mouth. (Photo: Ken Cantania)

Catania is the first scientist to study the interaction between prey and predator with the help of a high-speed camera. When he began to study the movement of the snake and its prey at slow speed, he discovered something very strange. When the fish fled, most of them turned towards the snake's head and many of them rushed into its mouth!In 120 trials with 4 different snakes, he found that 78% of the prey turned towards the snake's head.

Next, the biologist saw that the first part of the snake's body movement was not the first to have it. Instead, it bends a point in the middle of the body. Using an underwater stethoscope he confirmed that this part of the body creates a sound wave strong enough to stimulate the fish's 'C-start ' reaction. Because these waves come from the opposite side of the snake's head, the reaction of the prey leads them directly into the snake's mouth.

Catania said: ' When C start starts, the fish cannot return. This snake has found a way to use the fish's escape ability to benefit itself. ' As he continued to study further, he also discovered something more remarkable. When attacking prey, this snake does not target the first position of the fish and adjust the direction of the fish's movement - the way most predators do. Instead, its head is directed at the position where it predicts the head of the fish will move.

Catania explained: 'The proof that most of this is the snake slipped. Not all target fish react with the C boot, and the snake always misses such fish. '

Cantania's next step will be to determine whether this predictability is available or learned. To accomplish this, he hopes to collect some newly hatched offspring and record their first attempt to catch prey.

The research is funded by the National Science Foundation.