Some Aspects of Nutrition in Parasites

Abstract

Some selected examples of food-getting mechanisms in animal parasites are reviewed. The range of adaptations includes: (1) mechanical devices for biting or sucking plus internal or external digestive capacity, (2) internal digestive capacities only, or (3) no mechanical feeding mechanisms and no digestive capacities. In the latter case, feeding mechanisms are restricted to absorptive capacity. Available data on absorption are briefly reviewed. Questions concerning the food of parasites in hosts are posed, and the following examples are analyzed to demonstrate the difficulties in answering these questions: Fasciola, hookworms, Trichuris, and some nematode parasites of vertebrates.