Squid

Squid is the common name for a group of carnivorous marine mollusks in the class Cephalopoda. Squids have elongated, slender bodies with triangular caudal fins .The common squid is often found in coastal regions along the eastern United States. Squid have five pairs of arms, or tentacles, with rows of suckers. The tentacles extend outward from, and surround, the mouth. Four pairs of their tentacles are about equal in length and are used to steer when swimming. One pair is somewhat longer and retractable, it is used to capture prey. The head of the squid possesses a funnel for exhaling water-jets from the mantle cavity, providing a means of rapid movement. Their nervous system is well developed, and the organism (along with their close relatives, the octopuses) possess large, image-forming eyes that are quite similar to vertebrate eyes. The squid breathes through gills. Squids are blue-blooded animals because their respiratory-system pigment is a copper compound rather than the red iron found in mammals .Squids are able to change color rapidly by contracting and expanding pigment granules, called chromatophores. Each chromatophore is a fluid-filled sac controlled by 20 to 30 muscles and controlled by nerves found in the mantle region. Squids also contain an ink sac, the contents of which can be released to hide the animals' retreat when scared or challenged. Although most squids are small, usually less than 30 cm in length, they can attain great size. In the North Atlantic, giant squids of the genus Architeuthis can reach up to 15.2 m in length, including tentacles, and weigh over two tons. Squid is a popular food in East Asia and Mediterranean regions. In the United States tons of squid is used as fish bait.

Meet A Giant Squid