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GEOGRAPHIC AND ENVIRONMENTAL CORRELATES OR REGIONAL POPULATION GENETIC STRUCTURE IN THE CENTRAL STONEROLLER (CAMPOSTOMA ANOMALUM)
Citation:
Bagley, M J., S A. Christ, S E. Franson, A. C. Leonard, AND G P. Toth. GEOGRAPHIC AND ENVIRONMENTAL CORRELATES OR REGIONAL POPULATION GENETIC STRUCTURE IN THE CENTRAL STONEROLLER (CAMPOSTOMA ANOMALUM). Presented at American Society of Icthyologists and Herpetologists, Kansas City, MO, July 3-8, 2002.
Impact/Purpose:
The objective of this task is to develop molecular indicators to evaluate the integrity and sustainability of aquatic fish, invertebrate, and plant communities (GPRA goal 4.5.2). Specifically, this subtask aims to evaluate methods for the measurement of:
fish and invertebrate community composition, especially for morphologically indistinct (cryptic) species
population genetic structure of aquatic indicator species and its relationship to landscape determinants of population structure (to aid in defining natural assessment units and to allow correlation of population substructure with regional stressor coverages)
genetic diversity within populations of aquatic indicator species, as an indicator of vulnerability to further exposure and as an indicator of cumulative exposure
patterns of temporal change in genetic diversity of aquatic indicator species, as a monitoring tool for establishing long-term population trends.
Description:
Environmental factors that impact population sizes, migration rates, mutation rates or selective forces can leave lasting genetic imprints on patterns of intraspecific genetic variation. This suggests that measures of genetic diversity may be useful indicators of the condition of natural ecosystems. We examined the distribution of RAPD (random amplified polymorphic DNA) fragments in Campostoma anomalum (central stoneroller) populations in relation to several measures of environmental condition to test this hypothesis. Genetic differentiation among 58 stoneroller populations in streams from the Eastern Cornbelt Plains Ecoregion (Midwestern USA) was very high. Genetic distances were strongly correlated with the straight-line distance between sites, suggesting conformity with an isolation-by-distance model. Average genetic similarity within populations (S{-w}) differed greatly among all populations and was strongly associated with individual watersheds. This suggested a strong historical component to differences in genetic diversity within populations. Neither a fish index of biotic integrity (IBI) nor the qualitative habitat evaluation index (QHEI) was significantly correlated with S{-w}. However, S{-w} was significantly correlated with both total species richness (r=-0.37) and sensitive species richness (r=-0.35), even when the data was corrected for spatial autocorrelation.