The family Cheloniidae, in the order Testudines (turtles), comprises the sea turtles, a group of marine reptiles adapted to life in the ocean. Members of this family have streamlined shells and flippers that make them strong swimmers, and they primarily feed on seagrasses, algae, jellyfish, and other marine organisms depending on the species. Cheloniids are widely distributed in tropical and subtropical oceans around the world, often undertaking long migrations between feeding and nesting sites. They play an important ecological role in maintaining healthy seagrass beds and coral reef ecosystems. Most species in this family are threatened or endangered due to habitat loss, pollution, and human exploitation.