Brian R. Murphy

Genetic Marker-assisted Restoration of the Presumptive Native Walleye Fishery in the New River, Virginia and West Virginia

Fisheries Outstanding Technical Paper

The increasing importance of the walleye (Sander vitreus) fishery in the New River, Virginia, and recent research findings showing persistence of a presumptive native stock motivated a seven-year program of hatchery-based restoration of the native fishery. Candidate spawners were collected from spawning areas, and DNA from fin clips was genotyped at two microsatellite loci. Candidates exhibiting alleles at the Svi17 and Svi33 loci that characterize the presumptive native stock were spawned. Their young were reared at one of four fish hatcheries in Virginia and West Virginia. Approximately...


Genetic Distinct Walleye Stocks in Claytor Lake and the Upper New River, Virginia

The increasing importance of the walleye (Sander vitreus) fishery in the New River, Virginia, and recent research findings motivated characterization of its genetic composition. Movements of radio-tagged fish suggested that walleyes living in Claytor Lake and the upper New River tend to spawn in different areas. In this study, allozyme, microsatellite DNA, and mitochondrial DNA genetic marker data were analyzed to assess population genetic differentiation among collections of New River walleye. The walleyes within Claytor Lake are a panmictic population, presumably resulting from years of...


Predatory Impact of Muskellunge on New River, Virginia, Smallmouth Bass

Stomachs of 171 muskellunge (Esox masquinongy) ranging in length from 358 to 1270 mm were examined to evaluate fish diet and to estimate through bioenergetics modeling the predatory impact of muskellunge on smallmouth bass (Micropterus dolomieu) in the New River, Virginia. Fifty-five percent of muskellunge stomachs examined contained food. Ninety percent of muskellunge stomachs that contained food contained fewer than six items. Muskellunge exhibited an ontogenetic shift in diet at approximately 800 to 900 mm, changing from a diet consisting primarily of cyprinids to one consisting...


Alternative Methods to Predict Fish Proximate Composition

We used a multiple linear regression approach to develop models predicting water, protein, and lipid content of bluegills (Lepomis macrochirus) under 4 measurement approaches varying in terms of time and money. Inputs were length, weight, relative weight, total body electrical conductivity, and water. Models predicting water and protein weights were very accurate (<5% mean error). No regression predicting lipid weight was accurate enough to be used as a predictor (>37% mean error). We then attempted to reduce inaccuracy by standardizing lipid weight 4 ways. No standardization...