Octopus

The Octopus: The word octopus means “eight feet.” Octopuses are solitary, eight-armed animals that live on the ocean floor. There are over 100 different species of octopuses. The Giant Octopus is the biggest octopus. This huge mollusk is up to 23 ft (7 m) from arm tip to arm tip, weighing up to 400 pounds (182 kg). The smallest is the Californian octopus, which is only 3/8 inch (1 cm) long.

Anatomy: An octopus has a soft body and eight arms. Each arm has two rows of suction cups. If it loses an arm, it will eventually regrow another arm. It has blue blood. An octopus has an eye on each side of its head and has very good eyesight. An octopus cannot hear.

Diet: Octopuses eat small crabs and scallops, plus some snails, fish, turtles, crustaceans (like shrimp), and other octopuses. They catch prey with their arms, then kill it by biting it with their tough beak, paralyzing the prey with a nerve poison, and softening the flesh. They then suck out the flesh. Octopuses hunt mostly at night. Only the Australian Blue-ringed octopus has a poison strong enough to kill a person.

Protection: Octopuses live in dens, spaces under rocks, crevices on the sea floor, or holes they dig under large rocks. Octopuses pile rocks to block the front of their den. The den protects them from predators (like moray eels) and provides a place to lay eggs and care for them (a mother octopus doesn’t eat during the entire 1 to 2 months she is caring for her eggs). In order to escape predators, octopuses can squirt black ink into the water, allowing the octopus to escape. Another defense that octopuses have is changing their skin color to blend into the background, camouflaging themselves. The octopus swims by spewing water from its body, a type of jet propulsion. An Octopus is probably one of the most clever animals in the ocean. You have probably seen pictures of them but in real life they can be huge enough to fill a room with very long arms called Tentacles.

The common octopus would be unique for its appearance alone, with its massive bulbous head, large eyes, and eight distinctive arms. But by far the most striking characteristic of the octopus is the wide array of techniques it uses to avoid or thwart attackers.

Its first—and most amazing—line of defense is its ability to hide in plain sight. Using a network of pigment cells and specialized muscles in its skin, the common octopus can almost instantaneously match the colors, patterns, and even textures of its surroundings. Predators such as sharks, eels, and dolphins swim by without even noticing it.

When discovered, an octopus will release a cloud of black ink to obscure its attacker’s view, giving it time to swim away. The ink even contains a substance that dulls a predator’s sense of smell, making the fleeing octopus harder to track. Fast swimmers, they can jet forward by expelling water through their mantles. And their soft bodies can squeeze into impossibly small cracks and crevices where predators can’t follow.

If all else fails, an octopus can lose an arm to escape a predator’s grasp and regrow it later with no permanent damage. They also have beaklike jaws that can deliver a nasty bite, and venomous saliva, used mainly for subduing prey.

Considered the most intelligent of all invertebrates, the common octopus is found in the tropical and temperate waters of the world’s oceans. They can grow to about 4.3 feet (1.3 meters) in length and weigh up to 22 pounds (10 kilograms), although averages are much smaller. They prey on crabs, crayfish, and mollusks, and will sometimes use their ink to disorient their victims before attacking

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