The octopus propels itself through the sea by squirting a jet of water through a funnel called a siphon. Some species can reach speeds of nearly 22 miles per hour (35kmh).
When swimming the octopus faces backward so it is streamlined. Octopuses along with squids are among the fastest animals in the ocean.
The funnel the octopus using for propulsion is located just behind the head. The funnel also expels water after the gills have extracted oxygen. The funnel can also discharge a confusing cloud of ink at an enemy before the octopus flees.
Octopuses are very intelligent. They are among the smartest of all invertebrates with highly developed brains and nervous systems. They are mollusks; other mollusks include the very slow and less intelligent slugs and snails.
Octopuses use their armlike tentacles to seize prey such as fish, mollusks, and crabs. An octopus has eight muscular, flexible tentacles or arms. There are suction cups on the lower surface of each tentacle. The tentacles also have touch and taste sensors that help the octopus determine if what it catches is edible. Tentacles can be extended in less than one-hundredth of a second to catch prey.
Octopuses have sharp, bill-shaped jaws that can cut and tear prey. They also have a toothed tongue that can draw food into the mouth. Some species can inject their prey with a toxic substance produced by their salivary glands.
Octopus can change colors from red to orange, to yellow, blue, black, green, or violet. This allows them to blend into their surroundings.
The largest species of octopus int he world is the giant Pacific octopus. It can grow to nearly 10 feet (3m) in length and weigh up to 600 pounds (272kg). It lives on the rim of the north Pacific Ocean from Japan to the Aleutian Islands and south to California.
The scientific name of the common octopus is Octopus vulgaris.