TANK CULTURE OF LARVAL SUNSHINE BASS

In 1995, two studies were conducted at the Marine Resources Research I nstitute, Charleston, South Carolina, that focused on development of t echniques to intensively rear larval sunshine bass, the hybrid of fema le white bass Morone chrysops and male striped bass M. saxatilis. Duri ng the first study, the rotifer Brachionus plicatilis was shown to be an acceptable first-food when fed at 10 organisms/mL in static black t anks receiving high surface illumination (mean, 600 Ix). It was furthe r demonstrated that larvae could be switched to a diet of just nauplii of Artemia sp. by at least day 8 posthatch. At the conclusion of the 8-d study, larvae fed Artemia nauplii earlier were significantly large r (9.12 mm total length, TL) than larvae fed rotifers through day 7 po sthatch (6.71 mm TL). However, there were no survival differences (mea n, 67.2%). During the second study, supplementation of the Artemia nau plii diet with a commercial larval feed offered no advantage to 12-d-o ld larvae, which had similar survival rates (mean, 92.0%) and sizes (1 5.3 mm TL) at the end of the 9-d study. However, it was not clear whet her the larvae ate the commercial larval feed. At the conclusion of th e controlled larval rearing studies, the small juveniles were placed i n industry scale tanks (1.9 m diameter x 0.8 m deep) and converted to a dry diet by day 32 posthatch. By age 46 d, 62.2% of the juveniles ha d survived the transition to a dry diet, and average size was 59.7 mm TL (average weight, 2.9 g). Combining results, cumulative survival fro m age 3-46 d was approximately 38%, which is comparable to that of ext ensive pond culture systems. The intensive tank culture techniques, wh en coupled with controlled spawning of domesticated broodstocks, shoul d allow year-round production of juveniles for use in the expanding hy brid striped bass aquaculture industry.