POND PRODUCTION OF PELLET-FED ADVANCED JUVENILE AND FOOD-SIZE LARGEMOUTH BASS

Pond production of 100-200 g advanced juveniles and 400-450 g food-siz e largemouth bass (LMB) was evaluated. Ten 0.04-ha ponds stocked with different densities and at different times with 4.3-11.6 g young-of-th e-year LMB were used to evaluate the production of advanced juveniles. Fish were trained prior to stocking to feed on 40% protein floating t rout pellets to satiation, twice a day, Ponds had no water exchange ex cept to compensate for evaporation and seepage losses and were provide d with emergency aeration. Regression analysis showed that gross yield increased from 2995 to 6008 kg ha(-1), fish growth decreased from 1.4 7 to 0.86 g day(-1) and mean harvest weight decreased from 204 to 88 g as stocking rates increased from 17 000 to 67 136 fish ha(-1). Feed c onversion ratio for advanced juveniles averaged 1.07 and was not affec ted by stocking rates. Average fish survival was 82%. In a second tria l, twelve 0.04-ha ponds were stocked with 62-g, 1-year-old LMB at 2470 and 7410 fish ha(-1). Feeding and aeration were managed as described in the previous trial. Gross yields were 738 and 1742 kg ha(-1) for th e low and high stocking rates, respectively (P < 0.01). Survival rates and feed conversion ratios were comparable (P > 0.10) at both stockin g rates (81% vs. 76% and 1.42 vs. 1.56, respectively). Fish growth and mean harvest weight were 1.47 g day(-1) and 370 g at the low density and 1.16 g day(-1) and 307 g at the high density rate, respectively. Y oung-of-the-year LMB seemed to feed more actively on pellets than did 1-year-old fish, which may be attributed to differences in fish size a nd age, differential effects of high water temperatures on feeding res ponse of young-of-the-year and 1-year-old bass, and influence of alter native natural foods and overwintering on the retainment of pellet fee ding behavior.