Epibiont

The blowholes of a gray whale, with barnacle epibionts

An epibiont (from the Ancient Greek meaning "living on top of") is an organism that lives on the surface of another living organism.^[1] An epibiont is, by definition, harmless to its host and in this sense, the interaction between the two organisms can be considered neutralistic or commensalistic (as opposed to, for example, parasitic, in which case one organism benefits at the expense of the other, or mutualistic, in which both organisms obtain some explicit benefit from their coexistence).

Although there is no direct effect of the epibiont to the host, there are often indirect effects resulting from this interaction and change in the surface of the host. This has been found to be especially important to marine organisms and aquatic ecosystems as surface qualities do impact necessary ecological functions such as drag, radiation absorption, nutrient uptake, etc.^[2] Examples of common epibionts are barnacles, remoras, and algae, many of which live on the surfaces of larger marine organisms such as whales, sharks, sea turtles, and mangrove trees. The host of the epibiont is typically referred to as the basibiont ("living underneath").^[3]

Types

• Epiphytes are plants that grow on the surface of other plants.
• Epizoic organisms are those that live non-parasitically on the surface of animals.^[4] Examples of epizoic species include mosses, algae, and fungi growing on Gymnopholus weevils, and bryozoans (moss animals) growing on other animals.

See also

• Epiliths, organisms that grow on rocks
• Zoochory, seed dispersal by animals
• Epiphyte, an organism growing on a plant
• Endosymbiont
• Epiphytic bacteria
• Epiphytic fungus

References