Octopuses use different tentacles for different prey (VIDEO)  

Another revelation about these amazing creatures

If the coordination of two hands and two legs in humans is difficult, imagine how impressive the tentacle manipulation of octopuses is. New research into these amazing creatures reveals how their tentacle control is simplified, choosing a specific tentacle for specific prey .

Observing two octopuses of the species Octopus bimaculoides , the researchers recorded their reactions when crabs and shrimp were dropped into their tanks. Octopuses were hidden waiting for prey. Repeating the experiment hundreds of times, it was revealed that the octopuses constantly used the second tentacle from the middle, on the side where the eye was observing the prey, to catch it. When necessary, they also used the adjacent tentacles.

Although the eight tentacles have the same anatomy and are considered equally capable, the use of the same tentacle indicates an evolutionary adaptation.

Crabs and shrimps move differently, at different speeds, causing octopuses to use different methods of attack. In the crabs they saw the second tentacle attack abruptly, while in the faster shrimp the approach was with more subtle movements of the second tentacle so that the shrimp did not perceive the movement. As soon as the second tentacle grabbed the prey, the first and third secured it.

As each octopus eye covers 180 degrees without overlap, it is possible that octopuses prefer to place the target in the middle rather than the edges of their visual field.

The next step for biologists is to analyze the activity of neurons associated with specific movements. They do not consider that the central nervous system of the octopus is involved in the movement of the extra tentacles to capture the prey and think that it is a reflex action.

A better understanding of the mechanisms of the octopus will help us to better design soft robots, especially submarines.

Octopuses are extremely strong. For them, grabbing a handle and opening a door is a breeze. If we can learn from octopuses, we will be able to apply our knowledge to create an underwater vehicle or soft robot applications.

The research was published in Current Biology .