LARVAL REARING AND WEANING TECHNIQUES FOR WHITE BASS MORONE CHRYSOPS

The effects of culture parameters of tank color and feeding regimes we re examined on larval white bass Morone chrysops during 1994-1995. Und er high surface illumination (998 lux), dark tank walls were essential for effective prey capture. Larvae reared in clear glass aquaria did not grow and had died by day 6 of the study. In contrast, 38.7% of the larvae reared in black-walled tanks were alive on day 24 and had grow n to 17.2 mm total length (TL). In another study, larvae were fed roti fers Brachionus plicatilis and Artemia nauplii in different feeding pr otocols. In one treatment only rotifers (10/mL) were fed day 1 (4 d po sthatch), rotifers and Artemia (3/mL) were fed days 2-4, and Artemia f ed days 5-15. This protocol produced similar growth (mean size 11.7 mm TL) and survival (mean 30.3%) as slower weaning times from rotifers t o Artemia. Juveniles (27-day-old, 17.2 mm TL) were converted to a dry crumble diet over a 14-d period by slow transfer from a combination di et consisting of live Artemia nauplii, frozen adult Artemia, plankton flakes and dry crumbles. Survival of fish weaned to the dry diet was 6 4.5 %. Most of the mortalities during the weaning period were fish wit h uninflated swim bladders which were cannibalized by larger fish. Usi ng the above tank culture techniques, white bass were reared to a mean size of 73.2 mm TL (mean weight 5.8 g) over a 73-d period. This essen tially closes the life cycle of white bass.