Infauna refers to the organisms that live within the sediment of ocean floors, riverbeds, and other aquatic environments. These creatures, which include species like worms, clams, and certain crustaceans, play a crucial role in the ecosystem by helping to aerate the sediment and recycle nutrients. Infauna can be found at various depths and are adapted to their specific habitats. They contribute to the food web, serving as prey for larger animals such as fish and birds. Their presence is essential for maintaining the health of aquatic ecosystems and supporting biodiversity.