noun, plural ep·i·fau·nas, ep·i·fau·nae [ep–uh-faw-nee] /ˈɛp əˌfɔ ni/ Ecology.
- the aggregate of animals that live on the surface of the bottom of an ocean, river, or lake, or are attached to other aquatic organisms or submerged rocks.
- Benthic animals that live on the surface of a substrate, such as rocks, pilings, marine vegetation, or the sea or lake floor itself. Epifauna may attach themselves to such surfaces or range freely over them, as by crawling or swimming. Mussels, crabs, starfish, and flounder are epifaunal animals. Compare infauna.