Squids, Octopuses & Cuttlefishes

Squids, octopuses (not "octopi"), and cuttlefishes are biologically classified as the "Coleoids," and are among some of the most intelligent animals on the planet. Generally considered as the driving force behind their intelligence, their active predatory lifestyle is complimented by an array of features, such as their eight arms (plus an additional 2 grasping tentacles in squids and cuttlefishes) and the ability to camouflage. The two grasping tentacles of squids and cuttlefishes are considerably longer than the eight accompanying arms, all of which are attached to the head, which is proceeded by the main body mass called the mantle. The arms and tentacles are lined with suction cups (as well as hooks on ends of the tentacles), which help to bring forth prey into the animal's sharp, parrot-like beak. They locomote by use of a water propulsion jet at the front of the mantle called the siphon. The eyes of Coleoids are very developed, and are similar to the eyes of vertebrates. Coleoids can change colors or emit light via the use of chromatophores in their skin. The chromatophores enable camouflage, distraction, and communication amongst members of a species, and can especially aid in communicative cooperation when hunting (as seen in the highly cooperative Humboldt Squid). The largest squids known are the Giant Squid (Architeuthis dux), and the Colossal Squid (Mesonychoteuthis hamiltoni), both of which can reach lengths over 40’ long, while the largest octopus on record, the Giant Pacific Octopus (Enteroctopus dofleini) can get a maximum arm width of 30'! The oldest potential Coleoid in the fossil record comes from the earlier part of the Devonian period of Germany (408-393 million years ago), and is named Naefiteuthis breviphragmoconus, though more fossil material is needed to confirm if it is a true member of the Coleoidea.