An octopus is a mollusk related to clams and oysters. It lives in many parts of the world, in both deep and shallow water. It is sometimes known as the devil-fish, but it is not a fish. It has a round body, large head, and large eyes. An octopus has eight arms. In size, octopi range from two inches to twenty-eight feet from arm tip to arm tip. They vary in color and are able to change color.
   Most octopi move around for food at night. Crabs are their favorite food although they eat other crustaceans and fish. Their strong beaked jaws are used for crushing shells of crustaceans.
   The octopus is able to swim rapidly, moving backwards and trailing its arms. It propels itself by ejecting water through a siphon-like structure. It can also walk rapidly along the ocean floor. For protection, it ejects an ink-like substance, coloring the surrounding water.
   The internal structure of the octopus is similar to that of a squid. The third right arm of the male is enlarged and modified as a copulatory organ. The female deposits eggs, either in rope-like strings or grape-like clusters, on the roof of its hiding place. It guards the eggs which hatch in six to eight weeks. Along the Pacific Coast, from Alaska to Lower California, Octopus bimaculatus may be found. This kind is less numerous today than formerly. It is generally gray with two large red spots on the back. Octopus bairdi is found along the Atlantic Coast. This kind is bluish-white speckled with brown. It has a three-inch body and an arm span of forty inches.