The octopus plural: octopuses, octopodes or octopi; see below) is a cephalopod mollusc of the order Octopoda. It has two eyes and four pairs of arms and, like other cephalopods, it is bilaterally symmetric. It has a beak, with its mouth at the center point of the arms. It has no internal or external skeleton (although some species have a vestigial remnant of a shell inside their mantles),[3] allowing it to squeeze through tight places.[4] Octopuses are among the most intelligent and behaviorally diverse of all invertebrates.
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