J. A. Prentice

Scales and otoliths from largemouth bass (Micropterus salmoides) of known ages (age 6, 7, and 8) were prepared and examined by 3 experienced readers who were uninformed of specimen age or length. Results indicated limited agreement between readers and numerous inaccurate age estimations. Among 97 scale samples read, all 3 readers only agreed on the age of a single specimen which was older than estimated; using otoliths, readers agreed on 4 specimens which were correctly aged. Percentage of correctly-aged fish ranged from 10% to 30% with scales and 39% to 47% with otoliths. Percent of fish...

Post-stocking survival, biomass, food habits, growth, and angler utilization of orangemouth corvina (Cynoscion xanthulus) (OMC), spotted seatrout (C. nebulosus) (SST) X OMC hybrids, and OMC X SST hybrids were monitored from 1986 to 1990 at Calaveras Reservoir, a south Texas urban impoundment, after introductions from 1984 to 1986. Survival was excellent for all introduced fishes. Peak catch per unit effort by gill nets coincided with peak biomass estimates determined from cove rotenone sampling in 1987. Although similarly dense populations of blue tilapia (Tilapia aurea) and shad (Dorosoma...

Two bluegill subspecies (common bluegill Lepomis macrochirus macrochirus and coppernose bluegill L. m. purpurescens) were subjected to cold tolerance tests in the laboratory. Juvenile and adult bluegills were exposed to water temperature decreases of 1°C/hour from acclimation temperatures of 20° and 30° C until loss of equilibrium. Response temperatures of both subspecies were similar; temperatures at which 50% oftest fish lost equilibrium were usually <1.0° C lower for common bluegill and overlapping occurred in fiducial limits. Bluegill acclimated to 20° C lost equilibrium at 0.6...

Cost:benefit of 3 walleye fisheries were evaluated in 3 Texas reservoirs. Costs to establish walleye fisheries included expenses for equipment and for labor to procure and hatch eggs, to rear fry or fingerlings, and to stock reservoirs. Benefits of walleye fisheries were determined by multiplying the monetary value of a man-hour of recreational fishing by number of manhours of walleye fishing as determined by creel surveys. At Meredith Reservoir, where low densities of fry were stocked as the lake initially filled, costto- benefit of 1:89 was achieved in 3 years. At Greenbelt Reservoir,...