The cephalopods don’t use every limb in the same manner, something they share with primates
Octopuses are among the most versatile animals in the ocean, thanks to their eight flexible, sucker-lined arms. While all arms can perform any task, new research shows that octopuses subtly divide labor between their limbs, using the front arms more for exploration and the back arms for movement. The findings, published on September 11, 2025, in Scientific Reports, provide the first detailed breakdown of wild octopus arm usage across multiple species.
How Octopuses Use Their Arms
Octopus arms contain most of the animal’s nervous system, making them the primary tools for movement, hunting, and environmental exploration. Marine biologist Chelsea Bennice and her colleagues analyzed 25 videos recorded between 2007 and 2015 in Spain and the Caribbean, documenting nearly 4,000 individual arm actions across several wild octopus species.
The researchers categorized behaviors into 12 action types, such as reaching, grasping, and raising. They also identified four arm deformations: elongating, shortening, bending, and twisting.
“Octopuses are ultimate multitaskers,” says Bennice, of Florida Atlantic University in Boca Raton. “All arms are capable of all behaviors and deformations. They can even use multiple actions on a single arm or several arms simultaneously.”
Front vs. Back Arm Specialization
Despite their ambidexterity, octopuses show slight specialization between front and back arms. The study found:
- Front arms: Used approximately 64% of the time, mainly for exploration and manipulating objects.
- Rear arms: Take the lead in locomotion tasks, including lifting the body or rolling along the seafloor in a conveyor-belt-like motion.
This division of labor resembles patterns seen in primates and rodents, though octopuses remain unique in their extreme flexibility and multitasking ability.
Interestingly, the researchers found no strong left-right bias in wild octopuses, challenging earlier laboratory studies that suggested handedness-like preferences. Instead, octopuses tend to move their arms in coordinated left-right pairs in natural settings.
Neuroscientist Cassady Olson, of the University of Chicago, noted: “Previous research suggested octopuses might have left-right arm dominance. The difference likely comes from laboratory versus wild conditions.”
Implications for Soft Robotics
Understanding octopus arm movements has applications beyond marine biology. Engineers studying soft robotics can draw inspiration from these highly flexible appendages. The study’s breakdown of small arm tweaks that produce coordinated movements could help design robots capable of multitasking in complex environments.
Bennice hopes to expand this research to other octopus species, such as the mimic octopus (Thaumoctopus mimicus), which has radically different arm proportions. Comparing arm behaviors across species may reveal how limb length and shape influence overall animal behavior.
“Different species have distinct arm proportions,” Bennice explains. “Studying them could inform both biology and engineering applications.”