Communications: Tank Culture of Larval Sunshine Bass

Abstract

In 1995, two studies were conducted at the Marine Resources Research Institute, Charleston, South Carolina, that focused on development of techniques to intensively rear larval sunshine bass, the hybrid of female white bass Morone chrysops and male striped bass M. saxatilis. During the first study, the rotifer Brachionus plicatilis was shown to be an acceptable first-food when fed at 10 organisms/mL in static black tanks receiving high surface illumination (mean, 600 lx). It was further demonstrated that larvae could be switched to a diet of just nauplii of Artemia sp. by at least day 8 post-hatch. At the conclusion of the 8-d study, larvae fed Artemia nauplii earlier were significantly larger (9.12 mm total length, TL) than larvae fed rotifers through day 7 posthatch (6.71 mm TL). However, there were no survival differences (mean, 67.2%). During the second study, supplementation of the Artemia nauplii diet with a commercial larval feed offered no advantage to 12-d-old larvae, which had similar survival rates (mean, 92.0%) and sizes (15.3 mm TL) at the end of the 9-d study. However, it was not clear whether the larvae ate the commercial larval feed. At the conclusion of the controlled larval rearing studies, the small juveniles were placed in industry scale tanks (1.9 m diameter × 0.8 m deep) and converted to a dry diet by day 32 posthatch. By age 46 d, 62.2% of the juveniles had survived the transition to a dry diet, and average size was 59.7 mm TL (average weight, 2.9 g). Combining results, cumulative survival from age 3–46 d was approximately 38%, which is comparable to that of extensive pond culture systems. The intensive tank culture techniques, when coupled with controlled spawning of domesticated broodstocks, should allow year-round production of juveniles for use in the expanding hybrid striped bass aquaculture industry.