PRODUCTION CHARACTERISTICS OF STRIPED BASS (Morone saxatilis) AND F1, F2 HYBRIDS (M. saxatilis AND M. chrysops) REARED IN INTENSIVE TANK SYSTEMS1

The aquaculture characteristics of striped bass (Morone saxatilis) and its white bass (M. chrysops) hybrids were compared in two intensive tank culture studies which utilized recirculated brackish water. In the first study, striped bass and F1 hybrids (original cross) exhibited similar growth and survival rates even though the F1 hybrids were stocked at a density (65 fish/m3) 93% greater than the striped bass. By day 219, striped bass had grown from 30 g to 593 g while F1 hybrid bass grew from 47 g to 636 g. Standing crops at this time were 15.6 k9/m3, and survival was 74.6% and 78.4% for the striped bass and F1 hybrid bass, respectively. By day 302, F1 hybrid bass had grown to 835 g and standing crop was 43.1 kg/m3. The second study demnstrated that F1 hybrid bass (reciprocal cross) grew more rapidly than either striped bass or F2 hybrid bass (F1 original x F1 original) when reared at the same density (31 fish/m3). Further, survival of the F1 hybrid bass was 100% at conclusion of this 287-day study in spite of intensive sampling every 21 days. Individual growth variation was substantial among the F2 hybrid bass and size frequency distribution at harvest was broad and non-modal. In contrast, striped bass and F1 hybrid bass exhibited more uniform growth and size frequency distributions at harvest approximated normal distributions. At completion of this study mean sizes of the F1, F2 hybrid bass, and striped bass were 506.6, 346.7 and 289.3 9, respectively. In summary, F1 hybrid (M. saxatilis and M. chrysops) bass possess a number of desirable characteristics which should make them attractive for aquaculture development.