Specieswatch: each octopus arm may have a mind of its own
One of the most remarkable creatures on the planet is the common octopus, or Octopus vulgaris, which is now well established in UK waters as our seas warm because of the climate crisis. It has three hearts, and eight limbs with 200 suckers that can feel, taste and smell its surroundings. Scientists remain divided over whether it has one brain or nine. In mammals, most neurons are in the brain, but with octopuses, two-thirds are in their body and arms, enabling each arm to do complex tasks, such as opening jars to obtain food, apparently independently from the central brain.
After much experimenting with underwater mazes and other contraptions, scientists concluded that octopuses could solve various problems with one limb and then communicate the experience to other arms via the central brain.
The creatures only live about two years, changing colour to merge into the background while wandering about the seabed eating shellfish and anything they catch. To escape being eaten themselves by sharks or fish such as cod they release ink and use a jet of water to escape to a hiding place. During winter storms, octopuses can be stranded on beaches and in rock pools. Rescuers report eye contact, possibly an attempt at communication, before they swim away.