Researchers from the Marine Biological Laboratory in Woods Hole, Massachusetts, sought answers to these and other questions regarding the fine (and not-so-fine) motor skills of octopuses. The team discovered that these creatures do not have a dominant limb like humans do. However, there is still a certain division of functions among their limbs.
The team meticulously analyzed a series of short videos filmed in the Atlantic Ocean and the Caribbean Sea. The cameras captured wild octopuses engaging in their typical activities, including crawling, swimming, and exploring their environment.
The scientists were interested in what each of the eight limbs was doing. It turned out that all of them were busy performing tasks. Moreover, each limb is capable of executing about a dozen different movements.
Roger Hanlon, a marine biologist and co-author of the study, expressed his astonishment: “All the limbs can do everything – and that’s truly impressive.”
It’s worth noting that octopus tentacles are not as specialized as those of many mammals, as reported by Independent. However, the three species studied showed a clear preference for using their four front limbs as hands in about 60 percent of cases. Meanwhile, the rear limbs were more often used for movements resembling walking, facilitating forward movement – in other words, like legs.
Mike Vecchione, a zoologist at the Smithsonian National Museum of Natural History who did not participate in the study, summarized the functional difference: “The front limbs do most of the exploratory work, while the rear ones are primarily for walking.”
Why It Matters
This was the first large-scale study examining the precise movements of limbs in wild marine animals. Unlike previous experiments that investigated octopus behavior in laboratory settings, this new work demonstrated that in their natural environment, these creatures engage all their tentacles in daily activities without exception.
Octopuses are shy and elusive creatures. They spend most of their time hiding in burrows, making the filming process require considerable patience from the researchers.
The limbs of octopuses are complexly structured. They serve as means of locomotion and environmental perception for these cephalopods. Each tentacle contains between 100 to 200 suckers – intricate sensory organs that are “analogous to human noses, lips, and tongues,” said Hanlon.
If a bites off an octopus’s tentacle, which often happens in the wild, the affected octopus has several backup options.
The results of the study were published in the journal Scientific Reports.
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