Correlation between the level of infection with Bunodera inconstans and Neoechinorhynchus rutili and behavioral intensity in female brook sticklebacks.

We investigated the influence of 2 intestinal helminths, Bunodera inconstans and Neoechinorhynchus rutili, on the development of female behavioral and morphological characters in brook sticklebacks. The number of N. rutili per female is positively correlated with standard length. Both the number of B. inconstans per female and the number of N. rutili per female are negatively correlated with the intensity of a female's aggressive response to an intruding female and are positively correlated with the intensity and duration of female courtship. The results of this study indicate that infection with N. rutili and B. inconstans may influence a female brook stickleback's ability either to compete for a mate or to sample from a large subset of territorial males.