Aim We evaluate the phylogenetic relationships and taxonomic validity of Atlantic species of Labrisomus , identifying the lineages currently assigned to L. nuchipinnis , and assessing the role of biogeographic barriers in shaping the evolutionary history and geographic distribution of the genus. Location Atlantic Ocean. Taxon Labrisomus . Methods We assembled an extensive mitochondrial and nuclear DNA dataset of Atlantic speci...

Walleye is an important sportfish across eastern North America, is commercially fished in the Laurentian Great Lakes region, and has been introduced outside its native range. Thirty-eight Walleye populations within six watersheds across the Eastern Highlands and other portions of the native range were screened at eight microsatellite DNA loci to better understand evolutionary history and to inform fishery management and conser...

Genetic diversity and divergence patterns of smallmouth bass Micropterus dolomieu spawning groups are analysed across its northern native range with mtDNA cytochrome b gene sequences and eight unlinked nuclear DNA microsatellite loci. Results reveal high levels of genetic variability and significant differences in allelic representation among populations ( mtDNA : mean ± s.e ., H D = 0·50 ± 0·06, mean ± s.e ., θ ST = 0·41 ± 0·...

Biological invasions comprise accidental evolutionary experiments, whose genetic compositions underlie relative success, spread and persistence in new habitats. However, little is known about whether, or how, their population genetic patterns change temporally and/or spatially across the invasion's history. Theory predicts that most would undergo founder effect, exhibit low genetic divergence across the new range and gain vari...

Whole‐body morphometrics and 15 nuclear DNA microsatellite loci were analysed for 158 Perca flavescens collected during the spawning season from four spawning locations in central Lake Erie, two along the northern shore and two along the southern shore, to evaluate fine‐scale variation (spanning 17–94 km). Results showed significant morphological and genetic differences among P. flavescens from the four locations. The magnitud...

Comparisons of a species' genetic diversity and divergence patterns across large connected populations vs. isolated relict areas provide important data for understanding potential response to global warming, habitat alterations and other perturbations. Aquatic taxa offer ideal case studies for interpreting these patterns, because their dispersal and gene flow often are constrained through narrow connectivity channels that have...

Catchment population structure and divergence patterns of the rainbow darter Etheostoma caeruleum (Percidae: Teleostei), an eastern North American benthic fish, are tested using a landscape genetics approach. Allelic variation at eight nuclear DNA microsatellite loci and two mitochondrial DNA regions [cytochrome (cyt) b gene and control region; 2056 aligned base pairs (bp)] is analysed from 89 individuals and six sites in the...

Population genetic relationships reveal the signatures of current processes such as reproductive behaviour and migration, as well as historic events including vicariance and climate change. We analyse population structure of native walleye Sander vitreus across North America, encompassing 10 nuclear DNA microsatellite loci, 26 spawning sites and 921 samples from watersheds across the Great Lakes, Lake Winnipeg, upper Mississip...

The Eurasian round goby Neogobius melanostomus ( Apollonia melanostoma ) invaded the North American Great Lakes in 1990 through ballast water, spread rapidly, and now is widely distributed and moving through adjacent tributaries. We analyse its genetic diversity and divergence patterns among 25 North American ( N = 744) and 22 Eurasian ( N = 414) locations using mitochondrial DNA cytochrome b gene sequences and seven nuclear m...

During the past two decades, the round goby Apollonia melanostoma (= Neogobius melanostomus ) has expanded its range via shipping transport and canals, extending north and west from the Ponto‐Caspian region of Eurasia and to the North American Great Lakes. Exotic populations of the round goby have been very successful in the Baltic Sea and the Great Lakes regions, exerting significant ecological changes. Our study evaluates th...

The racer goby Neogobius gymnotrachelus , along with several other neogobiin fishes, has been spreading north and west from its native Ponto‐Caspian range for the past two decades via shipping and canals. It has been predicted as a likely future invader of the North American Great Lakes, where it would join its neogobiin relatives – the round and freshwater tubenose gobies. The present study is the first to analyse the populat...

Analysis of population genetic relationships reveals the signatures of current processes such as spawning behaviour and migration, as well as those of historical events including vicariance and climate change. This study examines these signatures through testing broad‐ to fine‐scale genetic patterns among smallmouth bass Micropterus dolomieu spawning populations across their native Great Lakes range and outgroup areas, with fi...

Population genetic theory predicts that long‐term isolation of ‘living fossils’ in relic habitats might reduce genetic variability due to small population sizes and inbreeding. The recent description of a troglodytic ‘living fossil’ Congeria kusceri — the only known subterranean bivalve mollusc — from a genus thought to be extinct since the Miocene, offers a unique opportunity to examine this hypothesis. Here, we use DNA seque...

Population genetic variability and phylogeographical structure of the Dover sole, Microstomus pacificus (Teleostei: Pleuronectidae), were examined along the continental slope of the northeastern Pacific Ocean using sequences of the left domain of the mitochondrial DNA (mtDNA) control region. Six sites were sampled in three primary biogeographical provinces (based on surface water temperatures), ranging from the subarctic to th...

Mitochondrial (mt) DNA control region sequences were used to test the genetic and phylogeographic structure of walleye Stizostedion vitreum populations at different geographical scales: among spawning sites, lake basins, lakes, and putative glacial refugia in the Great Lakes region. Sequencing 199 walleye revealed nucleotide substitutions and tandemly repeated sequences that varied in copy number, as well as in sequence compos...