Saltwater invertebrates are animals that live in ocean environments and lack a backbone. This diverse group includes species such as jellyfish, octopuses, sea urchins, and coral. They play essential roles in marine ecosystems, contributing to food webs and habitat formation. These creatures can be found in various ocean habitats, from shallow coastal waters to the deep sea. Many saltwater invertebrates have unique adaptations, such as the ability to regenerate lost limbs or produce toxins for defense. Their study helps scientists understand ocean health and biodiversity.