Genetic Relationships among Populations of Florida Bass

Abstract

Florida bass Micropterus floridanus are endemic to peninsular Florida and co‐occur with largemouth bass M. salmoides in a natural intergrade zone in the northern portions of the state. In this study, we resolved the genetic population structure among populations of largemouth bass, Florida bass, and their interspecific hybrids from 48 lakes and streams across Florida, and we updated and refined the southernmost boundary of introgression. Nuclear (allozyme and microsatellite) and mitochondrial (restriction fragment length polymorphism) markers produced somewhat different results. Microsatellite genotypes alone and the combination of all nuclear genotypes resolved genetic structure among four regional groups within Florida: (1) northwest, (2) north‐central, (3) central‐west, and (4) south, central‐east, and northeast. Allozyme genotypes alone did not resolve well‐defined groups. The distribution of mitochondrial haplotypes suggested that populations from the St. Johns River drainage should be considered their own distinct group (rather than be included in the south—central‐east—northeast Florida group). Although mitochondrial markers failed to detect introgression throughout much of the intergrade zone, nuclear markers revealed an expected decline in introgression from west to east as well as from north to south. Largemouth bass alleles, however, were detected at low frequencies in 12 populations below the southern boundary of the accepted intergrade zone, some of which are the result of stocking. There was no evidence of nonrandom mating or selection against hybrids in the distribution of nuclear genotypes; however, the rarity of largemouth bass mitochondrial haplotypes suggests either assortative mating or reduced fitness in the progeny of female largemouth bass × male Florida bass crosses.

Genetic Population Structure of Shoal Bass within their Native Range

“…We identified five distinct genetic populations of Shoal Bass at the uppermost hierarchical level and some appreciable substructure below that level, which could be used to define relevant management units that recognize diversity within and among populations (Barthel et al. ; Hallerman et al. ).…”

“…A similar approach has been used recently with Florida Bass (Barthel et al. ; Porak et al. ) and Neosho Smallmouth Bass M. dolomieu velox (Taylor et al.…”

Effects of hatchery rearing on Florida largemouth bass Micropterus floridanus resource allocation and performance under semi‐natural conditions

“…were collected in south‐west Florida from the Hardee Lakes Fisheries Management Area, FL, via electrofishing. The collection site of the hatchery brood fish was in the same genetic management zone as these wild‐caught juveniles (Barthel et al ., ); therefore, genetic differences between wild and hatchery treatments should be minimized. Wild‐caught M .…”

Discovery and validation of gene‐linked diagnostic SNP markers for assessing hybridization between Largemouth bass (Micropterus salmoides) and Florida bass (M. floridanus)

“…They are among the most popular freshwater sport fishes in North America and have been widely translocated as part of large‐scale stocking efforts (Barthel et al . ). These stocking efforts have been particularly intense for the largemouth bass, now believed to be represented by two distinct species (Kassler et al .…”

“…; Johnson & Fulton ; Barthel et al . ). The rate and success of this hybridization appears to be the result of strikingly low selection (in the form of intrinsic genetic incompatibilities) against hybrids within Centrarchidae when compared with other taxonomic groups (Bolnick & Near ; Seyoum et al .…”