Organisms living in or on bottom sediments are called

• A. Detritivores
• B. Benthos
• C. Carrion
• D. Periphyton

Answer: (B)

Benthos refers to organisms that live on, below, or on the surface of the bottom substrate of a water body. This includes creatures that inhabit the sediment (infauna) as well as those found on the sediment’s surface (epifauna). Because the question specifies life in or on bottom sediments, benthos is the term that directly matches that habitat.

Detritivores describe a feeding role rather than a habitat; many organisms across habitats feed on detritus, so this term doesn’t specify where they live. Carrion is simply dead animal matter and a food source, not a habitat group. Periphyton consists of algae and microorganisms attached to submerged surfaces, often on rocks or plants, rather than organisms living within or on bottom sediments.