Stephen P. Quinn

Increased management of wild catfish stocks is imminent due to their growing popularity with anglers and commercial exploitation. Length-categorization systems, like those used for largemouth bass (Micropterus salmoides), would improve catfish stock assessment and facilitate comparison of results among years, gears, samples, and populations. Flathead catfish (Pylodictis olivaris) from the Flint River, Georgia, collected by electrofishing and those caught by fishermen were assessed with Proportional Stock Density (PSD) and Relative Stock Density (RSD) indices. Population PSD was 72,...

Abundance and growth rates of flathead catfish (Pylodictis olivaris) from the Flint River, Georgia, were investigated during 1985 to gain basic information for future implementation of management strategies. Pectoral fins were disarticulated, sectioned at the articulating process, photographed, and enlarged for aging. The Schnabel and Schumacher-Eschmeyer multiple census population estimators produced similar results: there were 7,647 and 8,013 flathead catfish ≥ 305 rom in the 50-km section of river, respectively. Biomass estimates were 23.2 and 24.3 kglha. Growth was very fast for the...

Stomach contents of flathead catfish (Pylodictis olivaris) from the Flint River, Georgia, were examined to gain information on basic life history of this introduced species and to assess potential impacts on traditional fisheries. Acrylic tubes and a flexible claw retriever were effective for observing and collecting stomach contents which were then analyzed by frequency of occurrence, percent composition by number, and percent composition by weight. Young-of-the-year catfish contained primarily aquatic insects and began eating crayfish, sunfish (Lepomis sp.) fry, and darters (Etheostoma...

Three battery-powered pulsed DC electrofishing units were built and used to collect flathead catfish (Pylodictis olivaris) in a 50-km section of the Flint River, Georgia, to study the dramatic population expansion of that species following introduction. Peak collecting efficiency was achieved at 20 Hz frequency and pulse width of 0.4-0.5 ms. Power of 250-350 volts and 3 amps were needed to collect flathead catfish effectively in conductivities of 80-155 umhos/cm. Fishing downstream in a figure-S pattern with a 12-m anode wire hanging from the stern was effective in a variety of depth,...