Cephalopods are one group of mollusks, and there are about 650 different types of cephalopods. The main types are octopuses, squids, cuttlefishes, and nautiluses. Readers will learn about cephalopods' bodies and life cycle, where they live, how they sense the world, what they eat, and more. The text also offers an up-close look at blue-ringed octopuses and giant cephalopods.