Patterson et al.: Age and growth of Lutjcinus compechanus 
621 
which agreement was not reached after the sec- 
ond reading were not assigned ages or included 
in the growth estimation. Precision estimates 
were 1.25% for APE, 0.90% for CV, and 0.64% 
for D after the second reading. 
A clear pattern exists in the marginal in- 
crement scores, demonstrating that one opaque 
zone is formed annually in winter (Fig. 4). Most 
otoliths had opaque margins by January and 
had translucent margins by June, thus, timing 
of opaque zone formation appears to be from 
January through May for most fish. Eight fish 
(of 118) sampled in November (1997) and six 
fish (of 66) sampled in December (1996) had 
opaque margins. Four fish (of 47) sampled in 
January (1997) had translucent margins. 
The oldest female sampled was 34.1 yr old 
and the oldest male sampled was 33.2 yr old. 
The female to male ratio was 1.1:1 overall but 
was 1.5:1 for fish between 10 and 20 yr old and 
3.4:1 for fish greater than 20 yr old (Fig 5, A and B). Von 
Bertalanffy growth functions for females and males mod- 
eled separately were 
Females: TL = 976( i_ e -°- 191<M) - 051) ) 
(P 3;735 = 21,952; P<0.001; r 2 = 0.99) 
Males: TL = 956(l-e-° 194( ' +0054) ) 
(P 3 . 726 = 19,058; P<0.001; r 2 = 0.99). 
Computed VBGFs were not significantly different between 
males and females (likelihood ratio test;P>0 2 df=1 =0.2879), 
therefore, sexes were modeled together. Von Bertalanffy 
growth functions computed for all fish and excluding tour- 
nament sampled fish were 
All fish: TL = 969( 1-^-° 192(M)020 >) 
<^ 3 ; 1 . 672 = 47 ’ 690 ; P<0.001; r 2 =0.99) (Fig. 6) 
Excluding tournament fish: TL = 1181(l-e _0 120(;+a652) ) 
n= 97 82 
- O 
O 
66 47 
O * 
translucent 
opaque 
31 31 78 77 57 97 
23 118 
O O 
17 41 
o O O 
• • 
• • 
SONDJ FMAMJ J ASONDJ FM 
1996 1997 1998 
Month 
Figure 4 
Plot of monthly margin edge scores of red snapper sagittae. Symbol 
size is relative to the percentage of fish with the corresponding margin 
edge score. Monthly sample size is given. 
(F. 
=43,550; P<0.001; r 2 =0.99). 
3;1,461 
The growth model including all fish was similar to other 
VBGFs estimated for GOM and southeast U.S. Atlantic 
red snapper (Fig. 7, Table 2). 
Weight-TL nonlinear regression models for females and 
males modeled separately were 
Females: Weight = (4.46 x 10 _9 )TL 3 18 
(P 1;73 = 42,577; P<0.001; r 2 =0.98) 
Males: Weight = (5.18 x 10~ 9 )TL 3 16 
(F 1;728 = 43,956; P<0.001; r 2 =0.99). 
Log-transformed weight-TL relationships were not signifi- 
cantly different between males and females (ANCOVA test 
for equal slopes; F 1 1 465 =1.54, P=0.2145; ANCOVA test for 
equal intercepts; P 1 1 465 =1.49, P= 0.2226), therefore, sexes 
were modeled together. The resultant nonlinear regres- 
sion model was 
400 
300 
a> 
t 200 
100 
k\ \\i Unknown 
■■■ Females 
Males 
Figure 5 
Distributions of age for (Al all sampled red snapper and 
( B ) all fish greater than 10 yr old. Legend in section A is the 
same for both distributions. 
