Performance comparison of geographic strains of white bass ( Morone chrysops) to produce sunshine bass

Abstract

White bass ( Morone chrysops) broodstock were obtained from three locations in the United States encompassing the native range of this species: Arkansas River, AR; Lake Erie, near Cleveland, OH; and Lake Poinsett, SD. In spring 1996, white bass eggs of each strain were fertilized with fresh semen from the same strain or with extended striped bass ( M. saxatilis) semen pooled from nine males collected from the Arkansas River. Each strain of white bass and sunshine bass (female M. chrysops×male M. saxatilis) was stocked at 500,000/ha as 4-day posthatch larvae into recently filled and fertilized earthen ponds (triplicated for white bass and quadruplicated for sunshine bass). The fish were offered salmonid fry meal (∼50% crude protein, CP) 21-day poststocking. Phase I fingerlings were harvested ∼40-day poststocking. Mean survival rates of sunshine bass (12.5%) were significantly higher than those of white bass (2.6%). No differences in survival rates existed within the white bass or sunshine bass groups. Phase II sunshine bass were subsequently stocked in triplicated ponds at 25,000/ha. The fish were fed to satiation twice daily with a 40% crude protein salmonid diet and harvested 100-day poststocking. Mean weights of Lake Erie sunshine bass (90.2 g) were significantly greater than those of Arkansas fish (58.4 g), but not South Dakota fish (69.0 g). Phase III sunshine bass were stocked in late autumn 1996 in quadruplicated ponds at 4900/ha and fed beginning the next spring in the same manner as in Phase II. In autumn 1997, ponds were harvested and all fish had reached marketable size with Lake Erie sunshine bass averaging 648 g, followed by Arkansas fish at 636 g and South Dakota fish at 566 g. These weights were not significantly different ( P>0.05). However, Lake Erie and South Dakota fish had significantly ( P<0.05) higher fillet (without ribs) dress-outs (37.3% and 37.8%, respectively) than Arkansas fish (34.6%). These results demonstrate the feasibility of raising sunshine bass to market size in earthen ponds in the north central region of the United States. Lake Erie white bass might offer some advantage as a source of broodfish relative to the strains compared and under the conditions in which they were raised in this study.