The common octopus is a mollusk belonging to the class Cephalopoda. Octopus vulgaris is one of the most studied of all octopus species, and also one of the most intelligent. It ranges from the eastern Atlantic, extends from the Mediterranean Sea and the southern coast of England, to the southern coast of South Africa. It also occurs off the Azores, Canary Islands, and Cape Verde Islands. The species is also common in the Western Atlantic.
Common octopus
O. vulgaris from the Mediterranean Sea
Common octopus, Staatliches Museum für Naturkunde Karlsruhe, Germany
Common octopus of Portugal
A cephalopod is any member of the molluscan class Cephalopoda such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt ink. The study of cephalopods is a branch of malacology known as teuthology.
Cephalopod
The primitive nautilus eye functions similarly to a pinhole camera.
A cuttlefish with W-shaped pupils which may help them discern colors
This broadclub cuttlefish (Sepia latimanus) can change from camouflage tans and browns (top) to yellow with dark highlights (bottom) in less than a second.
