Growth of Bluegill, Largemouth Bass, and Channel Catfish in Relation to Fish Abundances, Food Availability, and Other Limnological Variables

Bluegill, largemouth bass, and channel catfish are widely distributed and popular sports species. We assessed growth of sympatric populations of these species in 14 reservoirs throughout Illinois, and attempted to relate growth to environmental factors. Principal components analysis (PCA) classified the lakes using 20 morphometric and limnological variables. We examined growth rate relationships with the principal components, via correlations, and also developed simple and multiple regression models using individual variables. Using size-specific growth for two size classes, percent littoral zone of a lake was correlated with growth of both channel catfish (300 and 450 mm) and small bluegill (50 mm). Lake latitude was correlated with growth of large bluegill (150 mm). There were no significant correlations for either size of largemouth bass (100 and 250 mm). Our empirical relationships provide working models of fish growth and suggest testable hypotheses for future study. The models, when tested against independent data sets, will provide managers with useful tools for making inexpensive, a priori assessments of a fishery resource