Octopuses eat bottom-dwelling crustaceans. Squids eat fishes and shrimps. Some deepwater squids may be scavengers. Octopuses pierce the shells of their prey, injecting poison that causes paralysis. They then release salivary enzymes, loosening the meat from the inner shell.
Squids use their two specialized tentacles to quickly reach out and capture fishes.
They tear off bits of flesh and scrape the meat into their mouths with their beaks. Octopuses range in size from 1 cm to more than 5 m in length, while squids range from 1 cm to 20 m. Octopuses and squids can swim in any direction and can alter their course quickly. Squids use fins located on their heads to propel themselves when swimming at low speeds. These fins steer and stabilize the squids when moving slowly, and wrap around the body when they move quickly, by way of jet propulsion.