Marine invertebrates are animals without a backbone that live in ocean environments. They include a diverse range of species such as jellyfish, octopuses, sea urchins, and coral. These creatures play essential roles in marine ecosystems, contributing to food webs and habitat formation. Many marine invertebrates have unique adaptations for survival. For example, mollusks like clams and snails have hard shells for protection, while crustaceans such as crabs and lobsters possess exoskeletons. Their varied forms and functions make them vital to the health of oceans and the overall biodiversity of marine life.