No evidence of fisheries-induced evolution observed from Bluegill populations in small Kansas impoundments

ABSTRACT Objective Bluegill Lepomis macrochirus support recreational fisheries throughout much of their geographic distribution. One characteristic of the species is for males to exhibit alternative reproductive tactics to maximize production of progeny. These divergent strategies coupled with size-selective harvest by anglers create the potential for fisheries-induced evolution (FIE). As such, we sought to characterize genetic diversity of five fished and five unfished Bluegill populations to test for the occurrence of FIE. Methods Fin clips from 100 Bluegill across 10 populations in southeast Kansas were collected to examine genetic diversity and test for the occurrence of FIE associated with long-term selective harvest. Individuals were genotyped using genome-wide single-nucleotide polymorphism data via restriction site-associated DNA sequencing. Population genetic analyses were performed on three data sets: all individuals, females only, and males only. Results Genomic analyses from 92 Bluegill across the 10 populations demonstrated consistent observed heterozygosity across populations that was less than expected heterozygosity. As such, there was low genetic differentiation among populations, with over 94% of genetic difference explained by individuals within populations and no evidence of selection. Cluster analysis supported these findings of genetic overlap among populations by grouping individuals into one to three distinct genetic populations. Conclusions We found no evidence of FIE in either fished or unfished Bluegill populations. Rather, there was little genetic variation among the study populations except for one population. Combining controlled experiments with recent advances in describing the Bluegill genome would be useful for identifying the presence or absence of FIE in exploited Bluegill populations.