What type of species interaction is used when one organism benefits at the expense of another organism?

The interaction where one organism benefits at the expense of another is referred to as parasitism. In this relationship, the parasite derives nourishment or benefits from the host organism, which is harmed in the process. The host may experience a range of negative effects, from minor health disturbances to severe illness or death, depending on the type of parasite involved and the nature of the interaction.

In contrast, mutualism involves both species benefiting from the relationship, while commensalism describes a situation where one organism benefits and the other is neither helped nor harmed. Predation, on the other hand, specifically involves one organism (the predator) killing and consuming another organism (the prey) for food, which is a different type of interaction compared to parasitism. Therefore, in the context of an interaction that harms one species while benefiting another, parasitism is the most accurate term.