The latest research aims to thoroughly investigate how wild octopuses utilize their arms within their natural environments. This pioneering study correlates arm movements to the entire animal in intricate, real-world contexts by examining arm dynamics across various settings. The results indicate that all arms are capable of executing all types of actions, yet a distinct pattern of arm specialization was evident. The front arms primarily engage in movements that aid in exploration, whereas the rear arms focus on facilitating locomotion. Additionally, the octopus displayed remarkable adaptability, with a single arm executing multiple actions simultaneously, showcasing coordination among different arms—signifying advanced motor control.
Illustrations of 12 arm actions from various wild octopus behaviors. These cephalopods frequently employ multiple arm actions at once, either on one arm or across several. Image credits: Venice et al., doi: 10.1038/s41598-025-10674-y.
The structure of an octopus arm is intricate, comprising four distinct muscle groups oriented horizontally, vertically, diagonally, and circularly around a central nerve.
This arrangement allows the octopus’s arms to adapt in numerous ways, enabling a variety of actions essential for tasks such as hunting, locomotion, and self-defense.
Despite this complexity, there is still a limited understanding of how wild octopuses utilize and modify their arms.
In this new study, Chelsea Venice and her colleagues at Florida Atlantic University analyzed 25-minute video recordings of wild octopuses filmed in the Atlantic and Caribbean between 2007 and 2015.
The observed octopuses belonged to the species Octopus vulgaris or closely related species such as Octopus insularis and Octopus americanus.
The researchers documented which arms were used each time an octopus exhibited one of 15 distinct behaviors (like crawling).
They also noted the combinations of 12 different arm actions (e.g., curling) and four distinct deformations (e.g., extension) executed by each arm during these activities.
Researchers found that every octopus is capable of transforming all eight arms in four diverse ways, enabling every arm to perform all actions.
The study revealed that both sides of the body utilize arms equally, although the front four arms are more actively engaged than the rear four (64% versus 36%).
The front arms are primarily employed for exploring, while the rear arms primarily assist in movement.
Consequently, two actions are notably more frequent with the rear arms: rolling, where the arm glides along the seabed akin to a conveyor belt, and lifting, where the arm extends vertically downwards.
“Our findings are among the first to demonstrate that octopuses utilize specific limbs for designated tasks—a behavior previously only documented in primates, rodents, and fish,” stated the researchers.
“These discoveries could inform advancements in robotic arms designed to replicate the functionality of the octopus.”
This study was published this week in the journal Scientific Reports.
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Co Bennice et al. 2025. The flexibility of the octopus arm enhances complex behavior across various natural environments. Sci Rep 15, 31875; doi:10.1038/s41598-025-10674-y
Source: www.sci.news
