你知道苏东可以分为三种吗？好好看清楚，以后就知道怎么叫咯！
Cuttlefish, common name applied to cephalopod mollusks that have 10 tentacles, or arms, 8 of which have muscular suction cups on their inner surface and 2 that are longer and can shoot out for grasping prey, and a reduced internal shell enbedded in the enveloping mantle. The body is short, broad, and flattened. Cuttlefish are carnivorous and excellent at capturing prey with their arms. Although good swimmers, they are not as fast as the related squids , but like the squids cuttlefish have lateral fins used as stabilizers and for steering and propulsion. They swim by jet propulsion, forcibly expelling water through a siphon. During the day they lie buried in the bottom of the ocean; at night they swim and hunt for food.
Except for the squid genus Loligo, cuttlefish have the best cephalopod eyes, which are highly complex. When disturbed, cuttlefish eject a cloud of dark brown ink from an ink sac for protection. The ink gland and ink sac are specializations of the rectal gland. The ink is composed mostly of melanin and has been used as the artist's pigment, sepia. All cuttlefish are dioecious, i.e., the sexes are separate.
The common, worldwide, deepwater cuttlefish, genus Spirula, is considered a "living fossil" because it possesses a remnant of the external shell of the ancient cephalopods. These cuttlefish have a small, coiled internal shell containing a bubble of gas (nitrogen), which serves as a float in the ocean. The European cuttlefish, Sepia officinalis, possesses a degenerate internal shell composed of lime, which is popularly called cuttlebone. Within the narrow spaces between the thin septa of the shell are fluid and gas (mostly nitrogen), which give the organism buoyancy. These cuttlefish are found in the Mediterranean and E Atlantic. The cuttlebone is used for pet birds as a source of lime salts. Sepia are able to undergo a complex of color changes ranging from pink to brown with varying stripes and spots, usually displayed when they are disturbed. The eggs, deposited singly and attached by a stalk to objects on the ocean bottom, are extremely large, up to .6 in. (15 mm) in diameter. The smallest cuttlefish, Idiosepius, inhabits tide pools and attains a length of .6 in. (15 mm). Cuttlefish are classified in the phylum Mollusca , class Cephalopoda, order Sepioidea.
Squid, carnivorous marine cephalopod mollusk. The squid is one of the most highly developed invertebrates, well adapted to its active, predatory life. The characteristic molluscan shell is reduced to a horny plate shaped like a quill pen and buried under the mantle.
The mantle, the chief swimming organ of the animal, is modified into lengthwise fins along the posterior end of the body and projects forward like a collar around the head. As the mantle relaxes and contracts, the squid swims forward, upward, and downward. Water is expelled in jets from the muscular funnel located just below the head, propelling the squid backward in abrupt jetlike motions. Two of the ten sucker-bearing arms (used to steer in swimming) are tentacles that can seize prey, which is then cut into pieces by the animal's strong beaklike jaws.
The squid breathes through gills, and may emit a cloud of inky material from its ink sac when in danger. The circulatory and nervous systems are highly developed. The eye of the squid is remarkably similar to that of humans—an example of convergent evolution, as there is no common ancestor. Squids are also distinguished by internal cartilaginous supports. Some deep-sea forms have luminescent organs.
The common squid is found from Maine to the Carolinas, often moving in shoals. In the United States tons of squid are used for fish bait, particularly by the cod fisheries in New England. Squid is a favorite food in East Asia and in the Mediterranean area. Species range in size from about 2 in. (5 cm) to the proportions of Mesonychoteuthis hamiltoni, the colossal squid, which is the largest of all invertebrates and may attain a mantle length of 13 ft (4 m) and total length of 33–46 ft (10–14 m), and the giant squid, Architeuthis dux, which has a mantle length of 7.4 ft (2.25 m) and is known to reach 43 ft (13 m) in total length.
Squids are classified in the phylum Mollusca, class Cephalopoda, order Teuthoidea.
Octopus, cephalopod mollusk having no shell, eight muscular arms or tentacles, a pouch-shaped body, and two large, highly developed eyes. The prey (crabs, lobsters, and other shellfish) is seized by the sucker-bearing arms and pulled into the web of tissue at the base of the arms, paralyzed and partially digested by a poisonous salivary secretion, and chewed by the horny, beaklike jaws and the radula, or tooth ribbon. Octopuses move by pulling themselves along with their arms or by forcibly expelling water through the funnel or siphon in the manner of their near relative, the squid. Sometimes they construct barricades of large stones; most hide in rocky crevices at the approach of danger or cloud the water by ejecting dark "ink" from the ink sac. They also change color (from pinkish to brown) according to mood and environment, sometimes exhibiting rapid waves of color changes that sweep over the body. The 3-ft (91-cm) American devilfish is found off Florida and in the West Indies; a smaller species that reaches only 2 in. (5 cm) is found N of Cape Cod. The common octopus of the Mediterranean and the Atlantic occasionally reaches 10 ft (3 m) in length; the giant octopus of the Pacific may have a diameter of over 30 ft (9 m). Octopuses reproduce sexually. One of the arms of the male is modified into a sexual organ that deposits spermatophores in the mantle cavity of the female. The eggs are encased in capsules and attached to a rock, where the female guards them. The young hatch directly, without a larval stage. Octopus is eaten in many parts of the world. Octopuses are classified in the phylum Mollusca , class Cephalopoda, order Octopoda, family Octopodidae, genus Octopus.
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