Arunas P. Liskauskas

Genetic Population Structure and Mixed-Stock Analysis of Walleyes in the Lake Erie–Lake Huron Corridor using Allozyme and Mitochondrial DNA Markers

Abstract We used allozymes and mitochondrial DNA (mtDNA) restriction fragment length polymorphisms to determine if spawning populations of walleyes Stizostedion vitreum from the Lake Erie–Lake Huron corridor are genetically differentiated and to estimate their contributions to a commercial fishery in southern Lake Huron (operated by Purdy Fisheries) in 1994 and 1995. Both types of genetic markers detected significant differentiation among walleyes collected from different sites, suggesting that fish from Lake Erie, Lake St. Clair, and Lake Huron are not a single, genetically homogeneous population. The combined use of both marker systems detected the greatest differentiation in pairwise comparisons of samples. Although some exceptions were detected, both marker types suggest a relationship between geographic proximity and genetic differentiation. The fish from Purdy Fisheries caught throughout 1994 had highly significantly different haplotype frequencies (mtDNA) but not allele frequencies (allozymes) from...

Mitochondrial DNA Variation and Stock Structure of Walleyes from Eastern Lake Huron: An Analysis of Contemporary and Historical Samples

Abstract The spatial and temporal distributions of mitochondrial DNA (mtDNA) haplotypes in walleyes Stizostedion vitreum captured from spawning stocks were examined to assess genetic population structure in eastern Lake Huron, Ontario. We also assessed mtDNA variation in pond-reared fish relative to that in their parental sources to determine whether cultured fish have the potential to influence mtDNA structure within and among stocks. Restriction fragment length polymorphisms in two polymerase-chain-reaction-amplified fragments totaling 7.6 kilobases and sequencing 310 base pairs of the control region were used to assess mtDNA variation in both archived scales and contemporary samples collected from 1965 to 1998. Although many stocks in eastern Lake Huron differed significantly in pairwise comparisons of contemporary haplotype frequencies, fish from eastern Georgian Bay and the French River complex exhibited low mtDNA differentiation. Low nucleon diversity (h) and the absence of low-frequency haplotypes ...

Comparison of Control Region Sequencing and Fragment RFLP Analysis for Resolving Mitochondrial DNA Variation and Phylogenetic Relationships among Great Lakes Walleyes

Abstract Direct sequencing of 513 base pairs from the control region and restriction fragment length polymorphisms (RFLP) in two fragments totaling 7.6 kilobases (fragment RFLP) that were amplified by polymerase chain reaction were used to assess mitochondrial DNA (mtDNA) variation in Great Lakes walleye Stizostedion vitreum. Our objective was to determine the effectiveness of these mtDNA markers in detecting genetic variation and resolving phylogenetic relationships among haplotypes previously identified by RFLP analysis of the entire molecule. The fragment RFLP analysis surveyed 554 base pairs and detected almost twice as many haplotypes as did the sequencing analysis. However, both approaches resulted in similar tree topologies and resolved the three major phylogenetic assemblages published in entire-molecule RFLP studies.

Spawning Season Distribution in Subpopulations of Muskellunge in Georgian Bay, Lake Huron

AbstractLoss of spawning and nursery habitats has been implicated as a major factor in the widespread decline of Muskellunge Esox masquinongy populations in North America. Although there is limited evidence of spawning site fidelity in Great Lakes populations of Muskellunge, such behavior could result in recruitment failure if individuals return each year to spawning sites that have become degraded. We compared the spawning behaviors of individual Muskellunge across three subpopulations in Georgian Bay, Lake Huron, to address the hypothesis that the use of specific spawning sites and spawning site fidelity are independent of the habitat’s suitability for successful recruitment. The study regions (southeastern, northeastern, and northern Georgian Bay) have experienced different impacts from human development and sustained low water levels. We radio-tagged 49 adult Muskellunge and tracked them for up to 3 years (between 2012 and 2015). Sufficient multiyear data were only acquired for 18 individuals in the s...

Pronounced Genetic Structure and Site Fidelity among Native Muskellunge Populations in Lake Huron and Georgian Bay

AbstractConservation and management issues related to genetic diversity and stock structure of native populations of Muskellunge Esox masquinongy have largely been unexplored. In Lake Huron’s North Channel and Georgian Bay, Muskellunge populations have been impacted by historical commercial fisheries, recreational fisheries, loss of spawning habitat, historical water quality issues, and ecosystem changes. To determine the spatial genetic structure of native Muskellunge in Lake Huron and Georgian Bay, spawning adults were sampled from 10 sites in the North Channel and eastern Georgian Bay. Genotyping with 20 microsatellite DNA loci showed substantial spatial genetic structure, with significant pairwise divergences among spawning sites. Individual- and population-based analyses revealed hierarchical population structuring, with strong patterns of spawning site fidelity and isolation by distance; very low levels of dispersal and gene flow over historical and contemporary timescales were indicated. Estimation...