Bottom-dwelling organisms living in or on sediments are called, often used to describe species that inhabit the substrate

• A. Primary Producers
• B. Benthos
• C. Scavengers
• D. Carrion

Answer: (B)

Bottom-dwelling organisms living in or on sediments are described by the term benthos. Benthos refers to the community that inhabits the bottom of a body of water—on, in, or right above the substrate—so it fits species adapted to living on or in the sediment, such as worms, clams, snails, and many small crustaceans. This contrasts with organisms that live in the open water column (pelagic), which aren’t tied to the bottom. The other options describe functions or food sources rather than habitat: primary producers are about energy capture, not where organisms live; scavengers feed on dead material, which isn’t inherently about being bottom-dwelling; carrion refers to dead matter, not a group of bottom-dwelling organisms. Benthos best captures the idea of bottom-substrate inhabitants.