TUCKER: ANCHOVY' AND SEA BASS ENERGETICS 



RESULTS 



Developmental Events 



Developmental phases were longer for black sea 

 bass at 20°C than for bay anchovies at 24°C (Table 

 1). Anchovy feeding behavior began within a few 

 hours after EP, and successful feeding was first 



observed 72 hours after fertilization. Sea bass feed- 

 ing behavior began several hours after EP, and suc- 

 cessful feeding was first observed at 133 hours. An- 

 chovy yolk lasted about 8 hours and sea bass yolk 

 about 47 hours after first feeding. Unfed anchovies 

 in 2 L dishes and 10 L tanks died 5.1 days after 

 hatching (6.2 days after fertilization) and unfed sea 

 bass in 10 L tanks died 8.2 days after hatching (10.2 

 days after fertilization). 



Table 1 .—Timing of bay anchovy and black sea bass developmen- 

 tal events (hours after fertilization). Starvation = 100% mortality. 



Bay anchovy 

 24-0 



Hatching (H) 

 Eye pigmentation (EP) 

 First-feeding success (FF) 

 End of yolk sac (EYS) 



Starvation (S) 



28 



60 

 72 

 80 



150 



Black sea bass 

 20°C 



48 



110 

 133 

 180 



245 



Length and Weight 



Throughout development, black sea bass were 

 heavier than bay anchovies of the same age and 

 length, but length at age, and trends in length and 

 weight, were similar. Sea bass egg weight was about 

 twice that of anchovies (32 ^xg vs. 15 jig; Figs. 1, 2); 

 at hatching, sea bass were heavier (22 ^g vs. 14 pig), 

 yet both species were the same length, 2.0-2.1 mm 



I- 



o 

 111 



60- 

 56- 

 52- 

 48- 

 44 

 40 3 

 36 

 32 

 28 

 24 

 20 

 16 

 12 

 8 



Black Sea Bass 



o^eggs 



^ig= 32.66-0.09646(hours) 

 R'=0.275 



»= unfed larvae 

 ijg = 28 02 e"° °°'*'^5<''°"''*' 

 R'=0 850 



& = fed larvae 



^g = 5.53 6 

 R'= 0.956 



,0 007264(hours) 



H 



EP 



EYS 



_l_ 



_l_ 



-L. 



_1_ 



_1 1 1 L_ 



~5o *5 60 So Tm 120 Tto ToS TaS 200 220 240 2eo 280 300 320 340 



HOURS AFTER FERTILIZATION 



Figure 2.— Dry weight of black sea bass eggs, unfed larvae, and fed larvae. 



283 



