Wilson and Nieland: Age and growth of Lutjanus campechcinus 
661 
Figure 6 
Observed total length (mm) at age and relationship of age to total length predicted from von Bertalanffy growth 
models for male (n=1438) and female (n = 1542) red snapper, Lutjanus campechanus, from the northern Gulf of 
Mexico. Closed circles and narrow line represent males; open squares and thick line represent females. 
or unweighted analyses (Fig. 7). All models predict rapid, 
and very much similar, growth during the first 8-10 years 
of life and slower growth thereafter. Asymptotic lengths 
among the above varied from 936 to 1025 mm. Our von 
Bertalanffy growth models also predicted a greater as- 
ymptotic TL and slightly faster growth for female red 
snapper. Among marine teleosts from the GOM, a similar 
pattern of growth has been shown for red drum, Sciaenops 
ocellatus (Beckman et al., 1988), sheepshead, Archosargus 
probatocephalus (Beckman et al., 1991), and cobia, Rachy- 
centron canadum (Franks et al., 1998). However, this phe- 
nomenon in red snapper may be the result of a prepon- 
derance of data from the commercial fishery included in 
our analyses. Owing to minimum size limits enforced in 
both the commercial and recreational fisheries, we had ac- 
cess to few red snapper less than age 2 and few less than 
250 mm TL. Conversely, the preference of commercial red 
snapper fishermen and wholesalers for smaller, plate-size 
individuals afforded us little opportunity to sample larger, 
and presumably older, red snapper; these are the individu- 
als that can influence estimation of k and which ultimately 
drive estimation of L x . The addition of another 20-30 old 
specimens of both genders could have profound effects on 
the estimations of L x for both sexes. Furthermore, growth 
studies of lutjanids in Australian waters (Davis and West, 
1992; McPherson and Squire, 1992; Newman et al., 1996) 
report faster growth and larger size at age among males. 
Proportionally greater expenditures of energy in the pro- 
duction of gametes by females is advanced to explain this 
observation (Newman et al., 1996). Thus, although the 
growth rates and asymptotic lengths for male and female 
red snapper are shown to differ statistically in our study, 
questions of the biological veracity and the biological sig- 
nificance of these differences remain unresolved. 
In addition to the differences in red snapper estimated 
growth rates between the sexes, there is an obvious high 
degree of diversity in individual growth rates. Owing to 
the large variability in age at a given TL (Fig. 6), this vari- 
able is a poor estimator of red snapper age. Our data in- 
dicate that red snappers of 400 mm, 600 mm, and 800 
mm TL could be ages 2-7 yr, 3-9 yr, and 5-35+ yr, respec- 
tively. As a more concrete example, consider the Interna- 
tional Game Fishing Association world-record red snapper 
caught by rod and reel, the otoliths of which were given 
to us for age analysis. This individual was caught off the 
coast of Louisiana by Doc Kennedy of Grand Isle, LA, on 
23 June 1996; it was 22.79 kg (50 lb, 4 oz) TW, 1039 mm 
(40.9 in) TL, and 965 mm (38 in) FL. Given the immense 
size of this specimen, one would reasonably expect it to be 
ancient by red snapper standards. However, our analysis 
