Largemouth bass (Micropterus nigricans) were stocked into two floating raceways (41 m3) and three ponds (0.04 ha) for a second season of growth. Fish were split into ponds and raceways from a common source. Mean weight of pond fish at stocking was 81 g and 111 grams in the raceways, 10 days apart. A Passive Integrated Transponder (PIT) tag was inserted into the abdominal cavity of 50 fish in each pond and 100 fish in each raceway at stocking. Fish in the ponds and the raceways were fed slow sink pellets (45% protein 20% fat) daily to apparent satiation. Water quality was monitored to maintain conditions for growth throughout the experiment with temperature and dissolved oxygen measured daily and total ammonia nitrogen, nitrite, pH, and alkalinity measured every other week. At the end of the growing season, fish were harvested to determine average weight, length, condition factor, survival, and yield. For each tagged fish recovered, weight, length, and sex was determined following euthanization and examination of the gonads. Samples from each sex and each production system were taken for proximate analysis.
Ponds were harvested after 161 days and raceways were harvested after 158 days. At harvest, mean weight for all fish in ponds was 356 g and 287g for all fish in raceways. Mean recovery of PIT tagged fish was 84.7% for ponds and 85% for raceways. Average weight gain among tagged fish in ponds was 270 g for males and 242 g for females. Average weight gain among tagged fish in raceways was 167 for males and 162 g for females. Preliminary analysis by sex reveals significantly greater weight gain in male fish grown in the ponds, and no difference in weight gain by sex for fish grown in the raceways. Condition factor for tagged pond fish at harvest was significantly greater than tagged raceway fish. No difference in condition factor was observed between tagged male and female fish in either system. Proximate body composition results will be reported in the presentation.