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 spp.) existed in the reservoir, OMC and hybrids fed exclusively on the shad. Growth rates based on known age and length at capture fitted to a von Bertalanffy growth model indicated both hybrids had faster growth than OMC; growth was rapid for all 3. Corvina grew to 46 cm TL in 1.5 years; the reservoir record was 5.81 kg. During the fishing peak, corvina harvest rates at Calaveras Reservoir were generally higher than Texas statewide averages for largemoufh bass (Micropterus salmoides) and channel catfish (Ictalurus punctatus), and much greater than rates reported for OMC in the Salton Sea, California.
