Genetic variation and conservation of stream fishes: influence of ecology, life history, and water quality

Abstract

Three stream-dwelling fish species were used to investigate effects of ecology, life history, and water quality on genetic variation. We sampled Etheostoma caeruleum, E. blennioides, and Campostoma anomalum from six streams of varying water quality. Allozyme electrophoresis revealed that the most ecologically specialized species, E. caeruleum, was the least variable (P = 68.4%, H-obs = 1.2%). Etheostoma blennioides was intermediate in specialization and variation (P = 77.84%, H-obs = 7.8%), and the least specialized species, C. anomalum, had the most variation (P = 90.0%, H-obs = 12.1%). This pattern conforms to Willis' niche-variation hypothesis and Selander and Kaufman's adaptation model. Differences in ecology, life history, and amount of genetic variation are responsible for differences in how variation is apportioned within and among populations and within and among rivers. Populations in the river with the worst water quality (Huron River) had the lowest within-population variation for each species; therefore, genetic variation mag. be a useful indicator of water quality. Lower genetic variation may result from selection associated with specific loci, e.g., PGM-2, in stoneroller minnows. However; indirect effects on population size probably contributed to the erosion of genetic variation. Ecology, life history, and pollution tolerance data combine as predictors of species' risk of genetic erosion.

Publisher

NRC Research Press

Publication Date

8-1-1997

Publication Title

Canadian Journal of Fisheries and Aquatic Sciences

Department

Biology

Document Type

Article

DOI

https://dx.doi.org/10.1139/cjfas-54-8-1822

Keywords

Exploratory analysis, Populations, Heterozygosity

Language

English

Format

text

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