It can be difficult to keep two arms and two feet coordinated. Octopuses not only have twice the number of limbs, but also more to handle. Their arms behaveAs if they had a mind all their own.
Recent research suggests that motor control can be made easier by using a preferred arm to catch prey.
Two-spot California octopusesOctopus bimaculoidesResearchers conducted experiments to determine the invertebrates’ reactions to shrimp and crabs that were dropped into their tanks. One eye was visible out of the den. Many video clips showed how the octopuses used the second arm in the middle to catch their prey. The neighboring arms were used when necessary.
The researchers wrote that even though the eight arms are of the same gross anatomy and are considered as equipotential, their use of the arm for specific actions could be a result subtle evolutionary adaptations. Published paper.
Shrimp and crabs move at different speeds and in different ways, so octopuses have to vary their attack methods. For crabs, for instance, a pouncing cat-like movement was used by the second arm. They scuttle slower than flitting shrimps..
The faster, more evasive shrimps preferred to be led slowly by the octopuses with the second hand, perhaps using subtle gestures to camouflage their movements.
“The Octopus is well-known for mimicry in foraging. We speculate that it may sway its arms near shrimps to establish a pattern of antenna and uropod sensory hairs. This could reduce the likelihood of the shrimp escaping with a tail-flick.” Researchers write.
After contact was established, the neighboring arms (numbered 1 and 3) were used to capture the helpless prey.
It was a surprise that the second arm attack was consistent. Although octopuses are often not coordinated, the researchers believe it has to do with their field vision, as suggested by earlier studies).
“The octopus’ 180 degree vision is a good indicator of its preference to position the target in the center of their visual field, rather than the borders. Write to the researchers.
Catching food in the wild is a matter of seconds. The octopuses have the potential to maximize their chances of catching it.
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Next, biologists need to determine how neuron activity can be linked to these precise motor movements. The scientists don’t think the octopus central nervous system is necessarily involved in recruiting additional arms to capture prey – instead it’s likely to be more of a reflex action.
The researchers believe that having a better understanding about the mechanisms behind arm coordination could be helpful in the development soft robots, especially for those who will be working underwater.
“Octopuses have a very strong constitution.” Trevor Wardill is a biologist, study author and researcher.From the University of Minnesota. Their dexterity makes it trivial for them to grab and open doors.
“If we can learn something from octopuses, we can apply that knowledge to make an underwater vehicle or soft robotic application.”
The research was published in Current Biology.
