The Chameleon Of The Sea

With a large, slimy head, eight arms and a beak, the octopusas Capt Nemo quickly discoveredis not to be tangledwith.

- David Profumo

BEAKED like a parrot, with three hearts, blue-green blood and a sex organ at the end of one arm, the common octopus is a bizarre, shy, jet-propelled mollusc that some regard as monstrous, but many believe is the world’s most intelligent invertebrate. Each year, one million pounds avoirdupois are harvested worldwide for the table.

Octopus vulgaris is a cephalopod or head-footed creature descended from ammonites. It’s cousin to the giant squid, which sports a 10in eyeball and is related to slugs and clams. Our population largely dwells around the English Channel, although it’s found more abundantly in warmer seas, notably the Mediterranean.

It has no skeleton and lost its protective shell way back in the evolutionary past. The large, slimy head is linked to eight, semiautonomous arms and conceals a tough chitinous beak; the lidded, yellowish eyes are frequently remarked upon by divers as being strangely expressive, although, in fact, octopuses (octopi is incorrect, being a Latinised mangling of a Greek name) can also see through the photoreceptors in their skin.

This pixellated dermis contains 200 colour spots per square millimetre, which allows it to change appearence rapidly—one nickname is the ‘sea chameleon’, but, unlike that lizard, an octopus can control the behaviour of its chromatophores by muscular activity. These pigments often oscillate even after death.