Adults and nymphs of three species of mites (Unionicola abnormipes, U. fossulata, and U. serrata) co-occur in the bivalve hosts, Villosa villosa, V. vibex, and Uniomerus declivis, in St. Mark's River, north Florida. Monthly samples of mussels at three sites over three years established that mean infrapopulation sizes, prevalences, and frequency distributions of mites among hosts varied greatly between mite species. Adults of only one mite species fitted predictions derived from one published model of population regulation. All other mites exhibited characteristics of two different models because of variation between sites, years, and host species, indicating that current models of regulation of parasite populations are inappropriate for these mites. / Mite species had frequently higher abundances in one host species. De-mited mussels placed out monthly at each site showed that these higher abundances are achieved within a month. Recruitment varied greatly between sites, years, and months but, because it was consistently high, did not have a significant, final effect on mite abundances with two exceptions: no recruitment by U. abnormipes at one site and no recruitment by adult U. fossulata, which enter mussels as nymphs and remain in the same mussels after metamorphosis. Consequently, the significance of any interactions between mites depends on locality and time of year, but models often assume that recruitment rates do not vary significantly. / Two field experiments indicated that the low abundance of U. abnormipes in the larger host species, Uniomerus declivis, was caused by competitive, and possibly predatory, interactions with U. serrata. However, U. serrata did not occur in Villosa villosa, in which U. abnormipes reaches its highest abundance, because most of these mussels are too small. Numbers of U. abnormipes are reduced also by adult U. fossulata but there is no evidence that U. fossulata prey upon U. abnormipes or exclude them from hosts. / Interactions between mites did not occur as predicted by either simple, theoretical models or more biologically-realistic ones developed for other systems but did demonstrate that experimental tests of models are essential. / Source: Dissertation Abstracts International, Volume: 49-06, Section: B, page: 2039. / Co-Major Professors: Daniel S. Simberloff; William H. Heard. / Thesis (Ph.D.)--The Florida State University, 1988.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76317 |
| Contributors | Downes, Barbara J., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 192 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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