Heupel et al.: Demographic characteristics of exploited tropical lutjamds 
421 
Figure 1 
Map of the Great Barrier Reef region off the east coast of Australia 
showing the four sampling regions where lutjanids were collected for 
use in this study. 
ic characteristics of many lutjanid species 
(but see Newman et al., 1996, 2000a; Kaun- 
da-Arara and Ntiba, 1997; Kritzer, 2002, 
2004; Amezcua et al., 2006; Marriott et al., 
2007). Many species remain unstudied and 
comparisons among species are few, even 
though research has covered much of the 
family’s geographic range, including Mexico 
(Arreguin-Sanchez and Manickchand-Heile- 
man, 1998; Amezcua et al., 2006), Kenya 
(Kaunda-Arara and Ntiba, 1997), the United 
States (Wilson and Nieland, 2001; Meyer et 
al., 2007), Japan (Shimose and Tachihara, 
2005), the Great Barrier Reef (Newman et 
al., 1996, 2000a; Marriott et al., 2007), Ara- 
bian Gulf (Grandcourt et al., 2006), and the 
Indian Ocean (Newman and Dunk, 2003; 
Pilling et al., 2000). The few data that do 
exist indicate that at least some lutjanid 
species are long lived with life spans over 
30 years (Newman et al., 1996; Wilson and 
Nieland, 2001; Newman and Dunk, 2003; 
Marriott et al., 2007). 
In this study we compared the demo- 
graphic characteristics of seven lutjanid 
species on mid and outer shelf reefs of the 
Great Barrier Reef (GBR), Australia, as 
a case study of the implications for intra- 
family demographic diversity for managing 
multispecies fisheries. The species exam- 
ined included the following: chinamanfish 
[Symphoj'us nematophorus ]; green jobfish 
[Aprion virescens\\ dory snapper [Lutjanus 
fulviflamma] \ yellow-banded snapper [L. adetii]\ hump- 
back red snapper [L. gibbus]; brownstripe red snapper 
[L. vitta\; and Spanish flag snapper [L. carponotatus] . 
These species are among the most common lutjanids 
caught on the GBR after the highly valued red snap- 
pers (L. erythropterus, L. malabaricus, L. sebae) (New- 
man et al., 2000b). 
Demographic characteristics examined for each 
species included size, age, growth, mortality, and 
sex-specific patterns. Demographic parameters were 
compared to quantify differences in life history strat- 
egies among species and to infer the likely resilience 
of each species to fishing impacts. This information 
was used to assess whether common management 
measures would be appropriate across species within 
the lutjanid family. Such descriptive field studies also 
can be useful for providing the data sets to be used 
in meta-analyses for further developing our collective 
understanding of life history theory (e.g., Roff, 1984; 
Molloy et al., 2007). In this study we describe differ- 
ent aspects of biology across these closely related spe- 
cies. Samples from the same shallow coral reef habi- 
tats allowed us to control for taxonomic, geographic, 
and environmental effects to provide insight into the 
similarities or differences in life history strategies 
and thus theoretical trade-offs in evolved traits for 
moderate-size gonochoristic teleosts. 
Materials and methods 
Sample collection 
Individuals of the seven lutjanids considered here were 
collected during the effects of line fishing (ELF) experi- 
ment 1 (Campbell et al., 2001) between 1995 and 2005 
from four regions of the GBR spanning 7° of latitude: 
Lizard Island, 14°S; Townsville, 18°S; Mackay, 20°S; and 
Storm Cay, 21°S (Fig. 1). All fishing was done by hand- 
line with the same gear as that used in the operational 
commercial fishery, but survey effort was stratified to 
ensure roughly equal distribution around each reef and 
over two depth strata (above 12 m and below 15 m). Oto- 
liths (sagittae) and gonads of fish were either dissected 
on the day of capture and processed as described below 
or fish heads were removed from filleted fish carcasses in 
the field, frozen, and otoliths were dissected upon return 
to the laboratory. Otoliths of five of the seven species 
were examined for age analysis (A. virescens, S. nema- 
1 Mapstone, B.D., C. R. Davies, L. R. Little, A. E. Punt, A. D. 
M. Smith, F. Pantus, D. C. Lou, A. J. Williams, A. Jones, A. 
M. Ayling, G. R. Russ, and A. D. McDonald. 2004. The 
effects of line fishing on the Great Barrier Reef and evalu- 
ations of alternative potential management strategies. CRC 
Reef Research Centre Technical Report no 52, 205 p. CRC 
Reef Research Centre, Townsville, Australia. 
