Octopus are solitary creatures that live in dens on the seafloor, which trap their prey of bottom-dwelling crustaceans and mollusks, by using its eight arms lined with suckers. Habitat: Calamari swims in the open ocean waters, either alone or in schools, and uses its eight sucker-lined arms and two specialized tentacles to catch its prey, which consists of various fish and shrimp. When in danger, both use defense mechanisms, such as swimming away quickly, camouflaging themselves, and shooting ink at their predators. An octopus does not have a shell at all, while calamari has a small internal flexible backbone called a pen.
Like clams and oysters, octopus and calamari are mollusks (invertebrate sea creatures), classified as cephalopods, meaning “head-footed.” The ”arms,“ are connected to their heads, while the rest of the body is in front of the head.Ĭharacteristics: Cephalopods are physiologically similar to other mollusks, but the main difference is their lack of a shell. Octopus and Calamari live in saltwater from the tropics to temperate zones.