Heupel et al.: Demographic characteristics of exploited tropical lutjanids 
429 
4 
5 
3 
• 
• • 
S. nematophorus 4 
\ * A. virescens 
2 
1 
3 
• \ 
X 2 
• • 
• • X • • i 
• \ 
• X* 
0 
Xv 
2 4 6 8 10 12 14 16 18 20 0 
2 4 6 8 10 12 
8 
6 
In frequency 
hO •&. O) 
\ 5 
L. carponotatus 
• 
4 
* . 
• 
2 
• 
• 1 
• 
L. gibbus 
• X. 
0 
o 
8 10 12 14 16 18 20 22 24 
6 8 10 12 
3 
L. fulviflamma 
2 
x. • 
1 
• • X s ^ • 
0 
• • 
5 8 10 12 14 16 18 20 
Age (yr) 
Figure 6 
Catch curves for five lutjanid species from the Great Barrier Reef between 1995 and 
2005. The slopes of the regressions provided estimates of the rate of total mortality ( Z ) 
for each species. 
cies, and L. gibbus was the only species taking greater 
than 10% of its longevity to attain 50% L m . Growth 
of L. carponotatus varied significantly among regions 
spanning 7° latitude, growing more quickly to smaller 
asymptotic lengths in the more equatorial regions than 
in the south. Although statistically significant, the dif- 
ference in growth may have little biological signifi- 
cance with varying only about 3% among regions. 
Regional variation in growth for the other species re- 
mains unknown because of a lack of data but results for 
L. carponotatus reveal potential environmental influ- 
ences on observed patterns for these other species. 
Mortality 
Estimates of mortality were likely biased because of 
selectivity of the sampling gear. For example, the posi- 
tively skewed age distributions for S. nematophorus 
and A. virescetrs indicate that older fish were less avail- 
able to the sampling gear and were likely to be under- 
