What Are The 2 Main Types Of Shelled Sea Creatures?

The two main types of shelled sea creatures are mollusks and crustaceans. Mollusks, such as snails, clams, and octopuses, typically have soft bodies and may possess hard shells for protection. Crustaceans, including crabs, lobsters, and shrimp, have an exoskeleton made of chitin that serves a similar protective function. Both groups play vital roles in marine ecosystems and human diets.