FISHERY BULLETIN: VOL. 84, NO. 4 



Table 2.— Mean standard lengths and wet weights of larvae of striped bass (SB), striped bass 

 x white bass (WBX), and striped bass x white perch (WPX) from specimens preserved at 

 6 d after hatching, immediately before the experiments began and at 30 d after hatching when 

 the experiments were terminated. 



'Differ significantly, P < 0.05, from both SB and WBX. ANOVA followed by SNK multiple comparison 

 procedure. 



2 Differ significantly, P < 0.05, from the 500 L~ 1 means. ANOVA. 



3 Differ significantly, P < 0.05, from all WBX and WPX mean lengths. ANOVA followed by SNK multiple 

 comparison procedure. 



"Differ significantly, P < 0.05, from all WBX and WPX mean weights. ANOVA followed by SNK multiple 

 comparison procedure. 



perch hybrid larvae were longer and heavier at the 

 500 L" 1 level (ANOVA, P < 0.05). At the 500 L" 1 

 food level the striped bass were significantly heavier 

 than either hybrid (ANOVA and SNK multiple com- 

 parison procedure, P < 0.05). The mean lengths of 

 30-d-old striped bass at 500 L _1 food level were 

 significantly longer than the mean lengths of the 

 hybrids (Table 2) (ANOVA and SNK multiple com- 

 parison procedure, P < 0.05). 



Growth Rates 



From 6 to 30 d after hatching larvae grew in 

 length at mean rates ranging from 0.28 to 0.36 mm 

 d _1 (Table 3, Fig. 1). There were no significant dif- 

 ferences in the growth-in-length rates among the 

 three types of larvae at the 500 L _1 Artemia food 

 level. 



The exponential regressions of mean weights on 

 age (Table 3, Fig. 2) gave instantaneous growth 

 coefficients ranging from 0.1396 to 0.1739 d _1 , 

 equivalent to 15-19% d~ : weight gains. None of the 



coefficients differed significantly from each other 

 (ANCOVA, P > 0.50). 



There were no significant differences in weight- 

 length relationships among types of larvae or be- 

 tween food levels (ANCOVA, P > 0.50). An average 

 relationship, based on the total regression compo- 

 nent of the ANCOVA, is W = 7.17 x 10 " 4 J 4 - 2399 . 



Enclosure Experiments 



Survival 



Survival of striped bass and hybrid larvae at 30 

 d after hatching ranged from 13.1 to 33.8% in the 

 nine enclosures. At 30 d there was no indication that 

 striped bass or either hybrid was superior in sur- 

 vival capability. The mean percentage survivals for 

 the three types of larvae ranged from 22.0 to 28.5% 

 (Table 4B) and did not differ significantly (ANOVA 

 on arcsin mean percent survivals). The mean over- 

 all survival rate for the three kinds of larvae was 

 25.0%. 



908 



