Propulsion primary mode of movement for squid
Classically, the squid has an elongated body, marked at one end with two fins used to stabilize it while it swims. It has 10 arms, including two longer tentacles, which are used for grasping and manipulating food. The body of a squid is covered with a mantle, a flexible layer of tissue which protects the delicate inner organs. Inside the mantle is the pen of the squid, a hard protrusion which is all that remains of the squid’s shelled ancestors.
Like many animals which live in the ocean environment, squid are capable of withstanding immense pressure, and can be found quite deep in the ocean. Giant squid in particular stick to the depths of the ocean, and may live out their entire lives in the dark of the deepest areas of the ocean. These squid have been estimated to reach lengths of up to 80 feet (25 meters), although living specimens of that length are difficult to recover. Periodically, a giant squid washes ashore or is caught in a fishing net, offering biologists an opportunity to study it.
Squid are carnivores, and they are also highly sought after as a food source. Humans eat squids in a wide variety of sizes, especially since every part of the squid except for the pen is edible. Squid flesh is slightly chewy and sweet, although it will be rubbery if it is prepared poorly. In nations which border the ocean, squid is a common ingredient in an assortment of dishes, from calamari to Thai squid salad.