Benthos

BENTHOS (from Greek benthos-depth), the community of marine or freshwater plants and animals, encompassing those forms which in their development are closely associated with the surface of the bottom, shores, and various underwater objects. Benthos includes both forms that are immovably attached - sessile algae, sessile infusoria, corals, sponges, some mollusks (for example, oysters), as well as free-living (erratic) forms, for example, many worms, insect larvae (for example, the midge-Chironomus), living in the mud, some crustaceans, many bottom-crawling mollusks. The benthos community in hydrobiology is contrasted with the plankton community (see). See also Biological analysis.