Nixon and Jones: Age and growth of larval and juvenile Micropogonias undulatus 
111 
>. 
o 
c 
0) 
C T 
0) 
Sep 87 
x =7.7(04) 
n = 1,620 
r n 
Dec 87 
x= 15 3(0 6) 
- 
1 n = 103 
| 
90 
80 
70 
60 
\0f 
o L 
50 
40 
30 
20 
10 
0 
50 p 
40 - 
30 - 
20 - 
10 - 
0 
50 p 
40 - 
30 - 
20 
10 
0 
x = 28 1 (17) 
n = 93 
x = 44.6 (1.3) 
n= 161 
x = 65 5 (1.9) 
n = 88 
x = 70 1 (1 4) 
n = 63 
x = 99 0(3 0) 
n = 85 
x = 91 1 (3 4) 
n= 31 
x = 83 5 (2 8) 
n = 44 
20 
160 
Standard length (mm) 
Age (days) 
Figure 3 
Monthly length- and age-frequency distributions for larval and juvenile Atlantic croaker 
collected from 21 September 1987 to 30 March 1988 in estuarine waters of Virginia. 
Also given are mean standard length and standard error in parentheses, ages and stan- 
dard error in parentheses, and sample size (n). 
August through October. Fish spawned earlier in the 
season are underrepresented in samples because they 
have experienced greater cumulative mortality than 
later spawned fish (Campana and Jones, 1992). Es- 
timates of size- and age-specific mortality are needed 
to predict hatching-date distributions more accu- 
rately, and these were not available. However, the 
result of greater accumulated mortality on early- 
spawned fish is to minimize the height of the esti- 
mated spawning peak. Hence, our results establish 
a lower bound of 82% of surviving juveniles spawned 
from August to October. 
