RELATIONSHIPS AMONG TOTAL WEIGHT, BODY SHAPE, VISCERAL COMPONENTS, AND FILLET TRAITS IN PALMETTO BASS (STRIPED BASS FEMALE MORONE-SAXATILISX WHITE BASS MALE MORONE-CHRYSOPS) AND PARADISE BASS (STRIPED BASS FEMALE MORONE-SAXATILIS X YELLOW BASS MALE MORONE-MISSISSIPPIENSIS)

Relationships among total weight (W), and linear measures of body shap e, visceral component weights, and fillet weight (Y) in market-size (> 454 g) palmetto bass (Morone saxatilis female x M. chrysops male, N = 138) and paradise bass (M. saxatilis female x M. mississippiensis male , N = 134) were determined with the allometric equation: Y = aW(b). Al lometric analysis was used to compare traits of palmetto bass and para dise bass, and to identify factors influencing fillet yield. Paradise bass, an all female hybrid, had deeper, thicker, shorter bodies, and s maller heads than palmetto bass females. Male and female palmetto bass had similar body shapes. Values of growth coefficients (b) for body s hape traits (range 0.21-0.48) indicated that shape was proportional ac ross the weight range of fish used. Mean visceral fat and ovary weight were higher In paradise bass than in palmetto bass females suggesting the reproductive cycle was more advanced in paradise bass females. Wh ole fillet (skin and ribs intact) and skinless fillet (ribs intact) we re larger for paradise bass than for palmetto bass, but trimmed fillet (skin and ribs removed) was not different between fish. Relative incr eases of whole and skinless fillet weights were greater than total wei ght in both groups indicating that the percentage of body mass attribu ted to fillet increases slightly as total weight increases. Therefore, small increases in fillet yield can be achieved by rearing fish to a larger size. Step,vise regression of whole, skinless, and trimmed fill et weight on body shape traits resulted in three parameter models with r(2)-values of 0.27-0.29 in palmetto bass, and of 0.37-0.43 in paradi se bass. Addition of visceral components as independent variables in t he models increased r(2)-values to 0.31-0.36 for palmetto bass and to 0.45-0.52 for paradise bass. Low phenotypic variation in fillet yield (CV = 36%) and poor predictability of yield from measures taken on liv e fish limit the potential for improving yield through individual sele ction. Identification of superior species or strain crosses or rearing fish to a larger size appear to be the best strategies for improving fillet yield of Morone hybrids.