Commensalism

Commensalism is an interaction between organisms in which one benefits while the other is neither helped nor harmed.

Epibiosis: A relationship in which one organism lives on the surface of another without parasitizing it. Some epibionts gain a surface or transport while their host remains unaffected.
Barnacle: A marine crustacean that attaches to hard surfaces and feeds by filtering particles from water. Barnacles attached to whales have often been treated as a case of commensal transport.
Parasitism: An interaction in which one organism benefits at the expense of another. Commensalism excludes the harm to the host that defines parasitism.
Ecological interaction: An effect of one organism on another organism's survival, growth, or reproduction. Commensalism is one possible pattern of effects within ecological interactions.
Inquilinism: A relationship in which one organism uses another organism or its structures as shelter. An inquiline gains a habitat inside or on another organism without harming it.
Remora: A fish with a suction disc that attaches to larger marine animals and other surfaces. Remoras gain transport and access to food scraps from larger animals.
Amensalism: An interaction in which one organism is harmed while the other is unaffected. It reverses commensalism's effect pattern: one is harmed rather than benefited.
Ecological network: A representation of ecological entities connected by feeding or other interactions. Commensal links may be difficult to detect within networks dominated by measured effects.
Phoresy: A temporary association in which one organism uses another for transport. The transported organism gains dispersal while the carrier is not affected.
Cattle egret: A white heron that often feeds on insects disturbed by grazing animals. The egret gains flushed prey, while the grazing animal is commonly considered unaffected.

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