Fig. 2.1 The relationships between SYMBIOTIC ASSOCIATIONS symbiotic associations. Most species are independent of other species or severe only one rely on them only temporarily for food (predators and their prey, for example) Some species form closer associations parasitism termed'symbioses'. Three major unilateral benefit categories can be seen commensalism, parasitism and mutualism, but each merges with the other: no definition separates one degree of benefit to absolutely from the others harm to the two the host commensalism mutualism species shelter and food benefit none symbIOSIS both (association between occasional C 100% dependence dependence closeness of association factors provided