DeVries and Grimes: Spatial and temporal variation in age and growth of Scomberomorus cavalla 
703 
sections exceeded their original estimates based on 
whole otoliths 67-100% of the time. 
The slightly higher maximum ages in the Atlantic 
than in the eastern or western Gulf during 1986-92 
may reflect lower fishing mortality rates for the At- 
lantic than for the Gulf where age structure was trun- 
cated by fishing pressure 4 ; alternatively, this find- 
ing may be a sampling artifact. A much higher pro- 
portion of Atlantic samples were collected at fishing 
tournaments, which target larger and older fish, and 
Atlantic sample sizes exceeded eastern and western 
Gulf sample sizes by 36% and 107%; therefore the 
chances of obtaining an older fish were greater. 
That females grew faster and attained larger maxi- 
mum sizes than males agrees with previous studies 
(Beaumariage, 1973; Johnson et al., 1983; Manooch et 
al., 1987; Collins et al., 1989; Sturm and Salter 1990). 
The large variation in ages within size intervals that 
we found was also noted by Johnson et al. (1983). 
Significant differences in growth among the three 
regions for both sexes during 1986-92 and the per- 
sistence of that pattern in each of the seven years 
support the hypothesis that there are three stocks 
as suggested by allozyme, mark-recapture, catch and 
fishing effort, and juvenile birth-date distribution 
data (Grimes et al., 1987; Johnson et al., 1994; Gulf 
of Mexico and South Atlantic Fishery Management 
Councils 3 ). That similar differences between Atlan- 
tic and eastern Gulf growth were present in 1977- 
78 is further evidence that these growth differences 
Table 5 
Total age distributions by 10-cm length class, by region, for all male king mackerel collected during 1986-92. 
Age ( yr ) 
olZG 
( cm ) 0 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 23 
n 
Atlantic Ocean 
35 
100.0 
4 
45 
100.0 
58 
55 
61.6 
37.6 
0.8 
125 
65 
13.7 
71.1 
14.8 
0.4 
263 
75 
0.8 
19.3 
43.0 
21.8 
10.0 
2.7 
1.1 
0.6 
0.3 
0.2 
0.2 
632 
85 
0.4 
3.5 
6.3 
16.8 
20.7 
12.4 
10.9 
7.6 
7.6 
5.4 
5.0 
0.9 
0.9 
1.1 
0.2 
0.2 
0.2 
0.2 
542 
95 
0.3 
0.9 
2.3 
5.8 
6.4 
7.3 
13.1 
11.3 
11.0 
13.1 
8.1 
7.8 
5.8 
2.9 
2.6 
0.3 
0.6 
0.3 
344 
105 
3.1 
3.1 
4.1 
2.0 
7.1 
5.1 
7.1 
11.2 
10.2 
11.2 
10.2 
9.2 
6.1 
4.1 
3.1 
2.0 
1.0 
98 
115 
6.2 
6.2 
12.5 
12.5 
18.8 
12.5 
6.2 
12.5 6 . 2 ' 
16 
125 
100.0 
1 
Eastern Gulf 
35 
45 8.8 
91.2 
57 
55 
74.8 
25.2 
155 
65 
13.9 
73.0 
13.1 
267 
75 
0.7 
27.8 
43.7 
19.0 
6.0 
1.8 
0.7 
0.4 
284 
85 
0.4 
8.4 
15.1 
24.4 
26.1 
9.2 
5.0 
8.0 
2.1 
0.4 
0.8 
238 
95 
1.5 
4.5 
4.0 
11.9 
14.9 
9.5 
18.4 
12.4 
6.0 
8.5 
5.0 
1.5 
1.0 
0.5 
0.5 
201 
105 
1.6 
3.1 
4.7 
7.8 
7.8 
17.2 
9.4 
17.2 
4.7 
10.9 
4.7 
3.1 
1.6 
3.1 
1.6 
1.6 
64 
115 
4.8 
9.5 
4.8 
14.3 
4.8 
9.5 
4.8 
9.5 
19.0 
4.8 
9.5 
4.8 
21 
125 
33.3 
33.3 
33.3 
3 
Western Gulf 
35 9.1 
90.9 
11 
45 
85.7 
14.3 
7 
55 
70.3 
28.4 
1.4 
74 
65 
9.3 
56.5 
29.0 
5.2 
193 
75 
2.1 
22.5 
33.9 
24.3 
11.4 
4.6 
0.7 
0.4 
280 
85 
1.3 
3.9 
11.3 
22.9 
23.4 
16.9 
10.8 
4.8 
3.5 
0.4 
0.9 
231 
95 
2.7 
7.5 
14.4 
15.1 
17.1 
13.0 
10.3 
6.2 
7.5 
2.7 
2.1 
0.7 
0.7 
146 
105 
2.5 
7.5 
15.0 
5.0 
5.0 
2.5 
15.0 
12.5 
7.5 
12.5 
5.0 
5.0 
2.5 
2.5 
40 
115 
11.1 
11.1 
11.1 
22.2 
11.1 
11.1 
22.2 
9 
1 This size class also contained one fish (6.2%) at age 24. 
