Organisms attached to surfaces like rocks and logs are called

• A. Periphyton
• B. Benthos
• C. Primary Producers
• D. Secondary Consumers

Answer: (A)

The main concept is the name for the community of organisms that attach to submerged surfaces in freshwater, such as rocks and logs. This attached community is called periphyton. It’s made up mainly of algae, cyanobacteria, and other microorganisms that form a slimy film on surfaces and photosynthesize, providing base-level food for many invertebrates.

Periphyton is distinct from benthos, which refers to bottom-dwelling organisms as a broader group (not all are attached to surfaces). It’s also specific about attachment, not about feeding style—so while periphyton includes primary producers, the term itself describes the surface-attached community, not just who eats who.