572 
Fishery Bulletin 96(3), 1998 
Table 5.1 in Grimes, 1987). Populations of L. peru 
studied in Baja California Sur and Michoacan off 
continental Mexico show this bias (1:0.82, n = 785; 
Ruiz Luna et al., 1985). In lutjanids, evidence sug- 
gests that skewed sex ratios probably reflect differ- 
ential growth and mortality between sexes (Grimes, 
1987). Other reproduction studies on lujanids have 
also suggested a tendency for females to be more com- 
mon at larger sizes. The population sampled in this 
study shows significant differences in mortality rates 
Table 4 
Age-length key used in the construction of the catch curves of Pacific red snapper, L. 
except for fish older than 15 years for which sectioned otoliths were used. 
peru 
Ages represent whole-otolith ages 
Length 
Group (cm) 
Age group (year) 
0+ 
1+ 
2+ 
3+ 
4+ 
5+ 
6+ 
7+ 
8+ 
9+ 
10+ 
11+ 12+ 
13+ 
14+ 
15+ 
16+ 
18+ 20+ 
21+ 26+ 
31+ Total 
10.1-15.0 
15 
8 
23 
15.1-20.0 
1 
107 
2 
110 
20.1-25.0 
50 
69 
8 
127 
25.1-30.0 
1 
58 
62 
121 
30.1-35.0 
4 
102 
17 
123 
35.1-40.0 
40 
70 
7 
117 
40.1-45.0 
9 
67 
37 
2 
115 
45.1-50.0 
17 
53 
26 
2 
1 
99 
50.1-55.0 
1 
9 
47 
26 
6 
1 
90 
55.1-60.0 
6 
8 
24 
23 
10 
3 
74 
60.1-65.0 
3 
11 
20 
9 
11 
3 
1 
58 
65.1-70.0 
1 
6 
17 
20 
7 
51 
70.1-75.0 
2 
5 
6 
4 
10 
8 
7 
1 
43 
75.1-80.0 
1 
2 
3 
6 
1 
1 
2 
1 
17 
80.1-85.0 
1 
1 
4 
1 
7 
85.1-90.0 
1 1 
2 
4 
> 90 
1 1 
Total 
16 
166 
133 
221 
172 
112 
86 
66 
61 
42 
41 
22 
13 
13 
6 
1 
3 
1 1 
1 2 
1 1180 
Table 5 
Comparison of growth parameters of Lutjanus peru obtained in studies from Mexico and Costa Rica (F-W=Ford-Walford plot, 
NL=nonlinear regression, n=sample size, LFA=length-frequency analysis, obs=observed lengths, back=back-calculated lengths, 
NA=not applicable). 
Reference 
A 
B 
C 
D 
E 
Study site 
Michoacan 
Michoacan Guerrero 
Oaxaca 
Baja California Sur NW Costa Rica 
(Los Cabos region) 
Baja California 
Sur (Bahia de 
La Paz region) 
Structure used 
scales 
scales 
scales 
NA 
otoliths 
Method 
F-W 
F-W 
F-W 
LFA 
NL 
Data 
obs. back 
obs. 
back 
NA 
obs 
L r (cm) 
81.5 79.5 
82.64 
66.71 
83.34 
92.85 
K (per yr) 
0.196 0.191 
0.11 
0.23 
1.46 
0.12 
t 0 (yr) 
0.725 0.786 
1.48 
-0.54 
0.04 
0.14 
n 
1068 412 
175 
208 
5902 
1180 
Age range (yr) 
1-7 1-7 
0-2 
0-8 
1-12 
0-31 
Size range (cm) 
23-62 24-64 
21-37 
20-59 
24-82 
10-99 
A = Ruiz et al. ( 1985); B = Aguilar Salazar ( 1986); C = Castro ( 1981 ); D 
= Gutierrez Vargas ( 1990); and E 
= this study. 
