Rats, Rattus norvegicus, were each infected with 30 female and either one or two male larvae of the parasite Moniliformis moniliformis (Acanthocephala). After an experimental period of 5 weeks, some of the female worms had been inseminated. Inseminated females were on average longer than uninseminated ones and occupied more anterior locations in the host's small intestine. As both of these features are associated with high fecundity, the pattern of mating adopted by male worms is consistent with the maximization of reproductive success. Insemination was non-random with respect to female size only in those populations where the male and female worms were relatively similiar in length. In populations in which the female worms were all much longer than the males, no significant differences in the size of inseminated and uninseminated females were found. Although several mechanisms could account for the patterns observed in the experiments, the evidence presented is most consistent with the hypothesis of active mate choice by males.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology