What does epifaunal mean?
"Epifaunal" is an adjective used chiefly in marine biology and ecology to describe animals that live on the surface of the seabed or of other submerged surfaces such as rocks, shells, wrecks, or pilings. Such creatures — collectively termed "epifauna" — include barnacles, sponges, bryozoans, sea stars, oysters, and many other sessile or slow-moving bottom-dwellers. The word contrasts directly with "infaunal", which denotes animals that burrow into soft sediment like mud or sand. Ecologists use "epifaunal" constantly when characterizing habitats: an epifaunal community may be described by its species composition, its coverage of hard substrate, or its role in filtering water and providing structure for other organisms. Because the term is precise and unambiguous, it appears throughout scientific literature on benthic ecosystems, from modern reef surveys to studies of fossil assemblages. Though technical in register, it is a valuable term for anyone reading about ocean life or marine conservation.
adjectiveRelating to or consisting of epifauna — animals that live on the surface of the seabed or of other submerged substrates, rather than burrowing into it.
- Of or relating to epifauna; describing organisms that live on the surface of the seabed or other submerged substrates.
"The rocky reef supports a rich epifaunal community of sponges, bryozoans, and sea stars."
"Divers recorded a dense epifaunal assemblage coating the wreck's hull."
"Epifaunal feeding strategies differ markedly from those of burrowing infaunal species."
Starfish, barnacles, and sponges all share one address: they're epifaunal — life lived entirely on top of the seafloor, never digging in.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of epifaunal
"Epifaunal" derives from "epifauna", a scientific compound formed from the Greek prefix "epi-" meaning "on" or "upon" and "fauna", from Fauna, the Roman goddess of fertility and wildlife, whose name came to denote the animal life of a region. The term arose within nineteenth- and twentieth-century biological classification to distinguish surface-dwelling bottom organisms from burrowing ones, paralleling the formation of "infauna". Its cognates include "faunal", "infaunal", and related ecological compounds built on "epi-" such as "epibenthic".
Related word forms
How epifaunal is actually used
A technical term used almost exclusively in marine biology, benthic ecology, and paleontology. It is nearly always found attributively (e.g., 'epifaunal community', 'epifaunal feeding'), and rarely appears outside scientific literature.
Easily confused with epifaunal
Infaunal describes animals that live buried within the sediment, whereas epifaunal describes those living on its surface.
Epiphytic refers to plants (or algae) growing on the surface of another plant, while epifaunal refers to animals on a substrate.