TUCKER: ANCHOVY AND SEA BASS ENERGETICS 



feeding and positive growth before their yolk is ex- 

 hausted. (Neither species had an advantage in sur- 

 vival time after yolk exhaustion; unfed larvae of both 

 species died within 3 days after EYS.) Starving sea 

 bass weighed 50% more than starving anchovies. 

 Time from hatching to starvation for unfed bay an- 

 chovies in both 2 L dishes and 10 L tanks was 122 

 hours (Table 1). Houde (1974) reported this period 

 to be 126 hours in 35 L aquaria. 



Growth of larvae might have been slightly reduced 

 by container size; however, anchovies and sea bass 

 were reared in the same tanks and the comparison 

 should not be affected by container size. 



Although growth in length was similar, sea bass 

 gained weight faster than anchovies (Table 7). At 

 hatching, sea bass weighed 1.6 times as much as an- 

 chovies. After 7 days of feeding, sea bass weighed 

 2.2 times as much as anchovies (Figs. 1, 2). At a 



Table 6— Energy budget for black sea bass eggs and lar\,-ae during growth and starvation. In the first column, 

 developmental events are indicated in parentheses. G, M, and F&U as percentages of I are given in parentheses. 



Age: from fertilization. 



Weight: measured 



Weight change from column 2 



Body calories = (weight) (estimated caloric content)- 



G = Growth calories = change in body calories. 



I = Food calories = {average feeding rate) (feeding time) (0.000787 cal/rotifer). 



M = Metabolic calories (measured mL Oz/h) (0 00431 cal/>iL O2) (36 hours). 



F&U = Egested and excreted calories = I - M - G 



Table 7.— Percent change in weight and energy content of bay anchovy and black sea bass during developmental phases. 

 Instantaneous growth rates are given. FF = First feeding. 



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