John A. Prentice

We evaluated the ability of oxytetracycline hydrochloride (OTC) and calcein (CAL) to double-mark otoliths in largemouth bass (Micropterus salmoides, LMB) fry and fingerlings. To observe longevity of marks, fish were sampled at six-month intervals for two years. Marks on fry otoliths disappeared rapidly regardless of chemical used; most marks were not visible after 180 days. Marks from CAL on fingerling otoliths were short-lived; 50% were not visible after 180 days. Marks from OTC on fingerling otoliths were visible on 100% of treated fish and were retained throughout the two years of study...

Growth, survival, and catchability of non-native coppernose bluegill (Lepomis macrochirus purpurescens) were compared to that of common bluegill (L. macrochirus) from East (Neches River system) and West (Rio Grande system) Texas populations. The 3 types of bluegills were stocked together (each identifiable by coded-wire tags) into 4 0.25- ha hatchery ponds. Bluegill types were evaluated with and without an established fish community present at age 1 and 2. Coppernose bluegill were larger (i.e., length and weight) than East or West Texas bluegills, regardles of fish community presence....

Triploid grass carp (Ctenopharyngodon idella) (N = 125, 50.8-98.6 cm total length [TL]) were implanted with radio tags and released into 5 reservoirs (25 fish each in Dunlap, McQueeney, Placid, H4, and H5) on the Guadalupe River, Texas. These fish were located periodically to determine specific movement patterns in and among the series of riverine reservoirs and the Guadalupe River system to provide an evaluation of their use and safety as an aquatic vegetation control tool. All grass carp survived tag placement surgery and stocking into assigned reservoirs. However, beginning 7 months...

A volunteer angler diary program was evaluated as a data source compared to traditional fisheries census techniques (i.e., electrofishing, gill netting, and on site creel surveys). Anglers were supplied fishing diaries and asked to record lengths of fishes caught, location, and time fished in Texas public waters, 1986-1988. Volunteer angler-supplied (ANG) length and catch-per-unit-effort (CPUE) data were then compared to traditional fisheries census data for the same season and water body. Although ANG data were reported for 4,581 trips, 144 reservoirs, and 10 species or species groups,...

Growth, survival, angler utilization, and fishery characteristics of red drum (Sciaenops ocellatus) were monitored after introduction into Braunig Reservoir, a freshwater urban power-plant cooling reservoir in South Texas. Growth was rapid with individuals reaching 412, 592, 683, and 728 mm TL by 12, 24, 36, and 48 months, respectively. Red drum reached harvestable size (51 cm TL) within 2 years after stocking. Average annual survival was 35.7%, higher than reported for Texas coastal populations. Red drum harvest rate was also generally higher in Braunig Reservoir than in Texas coastal...

This study was conducted to determine if water temperature increases during the walleye (Stizostedion vitreum vitreum) spawning period reduced egg hatch rate and if water temperature manipulation during egg fertilization would increase hatch rate. Walleye eggs were subjected, before and during fertilization, to 1 of 3 treatments involving water temperatures above and below 12 C. Water temperatures above 12 C were found to reduce hatch rates. Stripping and fertilizing eggs collected from reservoir water temperatures above 12 C into water chilled to 7.2 C significantly increased hatch rates...

Anhydrous ammonia was applied to ponds at average rates of 18-40 ppm to evaluate its use as a fish toxicant and aquatic herbicide. Ponds contained toxic levels ofammonia for 3-4 weeks after applications, depending on concentration, water temperature and other factors. A regression model was developed to estimate specific dissipation times. Application of15ppm ammonia effected a high percent mortality to all fish species observed. Complete fish kills occurred at approximately 30 ppm ammonia. Any concentration above 15 ppm temporarily controlled most vegetation, regardless of season. Benthic...

A study was conducted to determine the accuracy and validity of age determination methods for largemouth bass. Micropterus salmoides, and channel catfish, lcralurus punctatus, in central Texas farm ponds. Each pond selected for this study had been stocked only once with largemouth bass and/or channel catfish. Ages of fishes collected ranged from one through fouf years of age at the time of collection. Fish ages determined by the aging methods were compared to fish ages established by stocking dates. Overall accuracy of age determinations made by these methods was 94% for largemouth...