An octopus is a sea creature that has a soft, baglike body with eight legs. Its long, slender legs reach out in all directions.They have two large eyes with one located on each side of the head. They have good vision and can see well in the dark. Octopuses vary greatly in size. The smallest are only about 2 inches long. The largest may be 18 feet long and have a 30-foot arm span.There are more than 150 species, or types, of octopus. Each arm has two rows of cuplike suckers with great holding power. An octopus can change color quickly depending on its surroundings or its mood. It can be gray, brown, pink, blue, green, or even an angry red if it is suddenly frightened.

Octopuses live in seas throughout the world. They are especially numerous in the warm and cool waters of the tropics and temperate areas. However, some octopuses prefer cold water. Many octopuses, especially small species, live in relatively shallow waters near coastlines. Others, particularly large species, prefer the open seas. There they swim in the upper layers of the water and sometimes dive into the ocean depths. Most species are bottom dwellers, where they live and blend in with the rocks and sand of the ocean floor. Most octopuses are solitary animals and live alone.

Octopuses are carnivores, eating animals such as crabs, shrimp, and lobsters. Smaller and newborn octopuses eat plankton, tiny living things that drift in the water.. Larger octopuses often eat fish and other octopuses. An octopus usually crawls along the ocean bottom on its arms searching for food. Skillful hunters, octopuses also attack large prey such as sharks. If an octopus is in danger, it shoots a jet of water out of its body. This moves the octopus backward very quickly. An octopus also may release an inky fluid to darken the water and confuse an enemy. 

The octopus uses its arms and strong suckers to capture prey and to bring it to its beak. The beak is strong enough to crack most shells and to tear into the flesh of marine animals. Inside the beak is a tonguelike organ called a radula. It has rows of tiny teeth that help to extract the prey from its shell. The octopus can use the radula to drill into a shell if the beak can’t break it open. Near the octopus’s beak are salivary glands. Octopuses are able to inject venomous saliva into the drilled hole to paralyze the prey and to turn the flesh into a jellylike substance.

Many animals, including fish, seals, sea otters, and birds, prey on octopuses. Humans are also considered predators. They especially love fried calamari!