Zhao and McGovern: Variation in sexual maturity and sex ratio of Rhomboplites aurorubens 
841 
males (Fig. 1). During 1979-81 and 1985-87, the 
percentage of mature males at age 1 was significantly 
larger than that of females at the same age (Table 1; 
1979-81: Fisher’s exact test, two-tailed P=0.024; 
1985-87: G= 20.252, P<0.001). 
Sex ratios 
More vermilion snapper were caught by traps and 
hook-and-line in the depth range of 40-49 m than in 
other depth classes (Table 2). The trawl was gener- 
ally deployed in shallower water (20-39 m) than were 
traps and hook-and-line. These three gear types were 
deployed most often in latitude 32°N than in other 
areas (Table 2). To exclude the effects on sex ratios 
from varying latitude, fish length, years, and gear 
types, we used the data collected from the same lati- 
tude (32°N), length (200-249 mm or 250-299 mm 
TL), period, and gear when the independence be- 
tween sex ratio and depth was tested. Sample sizes 
in all categories were not always sufficient for a chi- 
square test. If the expected frequency of a depth-class 
was unacceptably low, that data was discarded from 
the contingency table. When sample sizes of depth 
Table 2 
Numbers of sexed vermilion snapper collected from May through August during 1979-93 by depth and latitude of sampling sites. 
Blanks indicate that no samples were available for that category. 
Period 
Depth 
midpoint 
(m) 
Traps 
Hook-and-line 
Trawl 
30°N 
31°N 
32°N 
33°N 
34°N 
Total 
31°N 
32°N 
33°N 
Total 
31°N 
32°N 
Total 
1979-81 
15 
3 
3 
25 
26 
26 
27 
10 
37 
5 
97 
102 
35 
1 
1 
5 
10 
27 
42 
242 
120 
362 
45 
8 
8 
326 
326 
55 
65 
Total 
26 
9 
35 
32 
346 
27 
405 
247 
220 
467 
1982-84 
15 
25 
21 
21 
6 
42 
48 
29 
217 
236 
35 
50 
50 
31 
31 
28 
28 
45 
298 
298 
214 
214 
55 
100 
100 
27 
27 
65 
7 
7 
Total 
469 
469 
6 
321 
327 
19 
245 
264 
1985-87 
15 
129 
129 
25 
13 
13 
283 
22 
305 
35 
1 
1 
173 
173 
45 
20 
367 
387 
145 
145 
55 
95 
95 
17 
114 
131 
65 
Total 
149 
462 
611 
30 
260 
290 
283 
195 
478 
1988-90 
15 
25 
44 
111 
80 
235 
50 
53 
27 
130 
35 
3 
13 
70 
86 
22 
12 
34 
45 
406 
23 
429 
226 
226 
55 
2 
153 
155 
118 
118 
65 
1 
1 
Total 
5 
57 
741 
103 
906 
72 
409 
27 
508 
1991-93 
15 
9 
9 
25 
155 
69 
81 
10 
315 
1 
1 
35 
104 
84 
155 
6 
349 
10 
4 
14 
45 
3 
124 
127 
35 
35 
55 
18 
286 
304 
14 
14 
65 
4 
4 
Total 
21 
259 
576 
236 
16 
1,108 
1 
59 
4 
64 
