FISHERY BULLETIN: VOL. 87, NO. 2, 1989 



lower temperature (15.5°C), northern anchovies lost 

 10% of their weight per day during the first 3 days 

 of starvation (Theilacker 1987), versus 17% per day 

 for bay anchovies (Table 5) and 11% per day for 

 black sea bass (Table 6). The greater ash content 

 of sea bass (Table 3) is probably related to their 

 greater size and consequent need for more struc- 

 tural material. 



Egg and larval caloric values calculated from prox- 

 imate analysis data (Table 4) are similar to bomb 

 calorimetry values for anchovy and sea bass eggs 

 and to published values for other species. Calculated 

 values for eggs were 5,512 cal/g for anchovies and 

 5,415 cal/g for sea bass (less than a 2% difference 

 from measured values, 5,477 and 5,315 cal/g). 

 Energy content of northern anchovy, Engraulis 

 mordax, eggs was 5,450 cal/g (Hunter and Leong 

 1981). Calculated values for larvae fed for 7 days 

 were bay anchovies, 5,465 cal/g, 6,079 cal/g ash- 

 free; black sea bass, 4,919 cal/g, 5,991 cal/g ash-free. 

 These numbers are within the ranges given by 

 Thayer et al. (1973) for postlarvae of four marine 

 fish species: 4,904-6,001 cal/g, 5,694-6,418 cal/g 

 ash-free. Ranges of calculated ash-free values were 

 5,771-6,088 cal/g for bay anchovies and 5,950-6,099 



cal/g for black sea bass. The possible effect of vary- 

 ing lipid and carbohydrate content is small. Houde 

 and Schekter (1983) used a constant value of 5,000 

 cal/g, and Theilacker (1987) used 5,400 cal/g in con- 

 structing energy budgets for larval fish. 



Patterns of oxygen consumption were generally 

 similar for the two species (Figs. 3, 4). The decrease 

 for black sea bass during the 0.5 day after hatching 

 probably resulted from reduced activity prior to the 

 development of vision. The interval between hatch- 

 ing and EP was shorter for bay anchovies (1.3 

 days vs. 2.5 days). Lasker and Theilacker (1962) 

 found that oxygen uptake in Pacific sardines in- 

 creased just after hatching, but was variable, 

 depending on activity. On the eighth day of feeding, 

 sea bass consumed oxygen at three times the rate 

 of anchovies. At that stage, sea bass had two and 

 a half times as much respiring tissue, and were more 

 active (Qo of sea bass was 12 fxL 02/mg/h vs. 9 

 for anchovies). However, at 20 ^g, bay anchovy and 

 black sea bass Qo„ was the same and was inter- 

 mediate among those of other species (Table 8). 

 Early bay anchovy oxygen uptake was similar to 

 that found by Houde and Schekter (1983), who 

 reported mean uptakes of 0.030 nL/hlegg and 



Table 8. — Comparison of growth characteristics of well-fed larvae of five species. 



regarding acronyms. 



See Tables 1 and 5 



'Theilacker 1987 (except capture success). 



'Houde 1974, Houde and Schekter 1980: Houde and Schekter 1983 



^Present study. 



■"Hunter 1972, 



290 



