SREL Reprint #0945




Microgeographic Genetic Organization of Populations of Largemouth Bass and Two Other Species in a Reservoir

Phyllis K. Kennedy, Michael L. Kennedy and Michael H. Smith



Biochemical variation encoded by three loci was assessed for largemouth bass collected over two years from eight sites evenly distributed around a reservoir receiving thermal effluent. Body conditions, which was positively correlated with body-fat level, was examined as an indicator of differential environments.  Thermal and temporal effects on body conditions were not seen for the genetic characteristics.  Sexual differences were not observed in body condition and were minimal genetically.  Samples of bass from different sites exhibited homogeneity of allelic frequencies, while previously reported data from similar sites indicated significant heterogeneity in bluegill and mosquitofish.  The degree of spatial genetic heterogeneity seemed related to body size highest heterogeneity in the smallest species (mosquitofish), lowest in the largest species (largemouth bass).  Allele frequencies for the samples were negatively correlated over short distances in each of the three species, this pattern could be explained be explained by strong selection in a patchy environment or by a tendency for differential dispersal of fish of various genotypes.


SREL Reprint #0945

Kennedy, P.K., M.L. Kennedy, and M.H. Smith. 1985. Microgeographic genetic organization of populations of largemouth bass and two other species in a reservoir. Copeia 1985:118-125.

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