阅读理解
Octopuses (章鱼) are sea animals famous for their rounded bodies, bulging eyes, and eight long arms. They live in all the world's oceans but there are especially more octopuses in warm, tropical (热带的) waters. Octopuses, like their cousin, the squid (乌贼), are often considered “monsters of the deep”, though some species, or types, occupy relatively shallow waters.
Most octopuses stay along the ocean's floor, although some species are pelagic, which means they live near the water's surface. Other octopus species live in deep, dark waters, rising from below at dawn and dusk to search for food. Crabs and shrimps rank among their favorite foods, though some can attack larger prey (猎物), like sharks. Octopuses typically drop down on their prey from above and, using powerful suctions that line their arms, pull the animals into their mouths. The octopus performs its famous backward swim by blowing up water through a muscular tube on the body called a siphon. Octopuses also crawl (爬) along the ocean's floor, putting their arms into small openings to search for food Seals, whales, and large fish prey on octopuses.
If threatened, octopuses shoot an inky liquid that darkens the water, confusing the other animals. The octopus can also change to gray, brown, pink, blue, or green to mix with its surroundings. Octopuses may also change color as a way to communicate with other octopuses. Octopuses are solitary creatures that live alone in dens (巢穴) built from rocks, which the octopus moves into place using its powerful arms. Octopuses sometimes even fashion a rock “door” for their dens that pull closed when the octopus is safely inside.
