epibionte

An epibionte is an organism that lives on the surface of another organism, the host. This type of ecological relationship is known as epibiosis. The epibionte is not typically parasitic, meaning it does not cause significant harm to its host, although some epibiotic relationships can exist on a spectrum with parasitism. The epibionte benefits from its position on the host, which can provide a stable substrate for attachment, access to food sources, or protection from predators. In return, the host may experience minimal to no negative effects, or in some cases, may even derive a benefit from the presence of the epibionte, such as camouflage or improved nutrient uptake.

Examples of epibiontes are diverse and found across various ecosystems. Algae and cyanobacteria commonly colonize the surfaces of rocks, plants, and marine animals. Barnacles are a classic example of epibiontes, attaching themselves to the shells of turtles, whales, and even ships. Bryozoans, small colonial invertebrates, often grow on submerged surfaces, including seagrasses and the exoskeletons of crustaceans. The relationship can be facultative, where the epibionte can survive independently, or obligate, requiring the host for survival. Understanding epibiotic relationships is important for comprehending ecological interactions and the flow of energy within communities.