Competition between the rat tapeworm, Hymenolepis diminuta, and the acanthocephalan, Moniliformis dubius, in the laboratory rat
Holmes, John Carl
Doctor of Philosophy
Since the tapeworm, Hymenolepis diminuta, and the acanthocephalan, Moniliformis dubius, are thought to obtain all their nutrients by absorption through the body surface, are known to inhabit the same general part of the rat intestine, and require carbohydrate from host ingesta for growth and reproduction, competition for nutrients and/or specific habitat sites should be demonstrable in this host-parasite-parasite system. This may be important as a factor in the regulation of the distribution and abundance of endoparasitic helminths. A study was therefore undertaken to investigate the interactions, especially the possibility of competition, between H. diminuta and M. dubius in the rat. More specifically, the study has three aims: (1) To study the effects of concurrent infection on H. diminuta and M. dubius . (2) To determine whether the effects demonstrated are due to the production (by one or both of the helminths) of toxic metabolic products, to changes in host physiology in response to the presence of one or both of the helminths, to competition for space, or to competition for some essential metabolite(s) that is (are) relatively scarce in the intestine. (3) To determine the physiological basis for the effects demonstrated.