Spanik et al.: Using DNA barcoding to improve taxonomic resolution of the diet of Lutjanus campechanus 131 
Figure 5 
Generalized diet composition by prey category, according to index of relative 
importance (IRI) values based on examination of stomach contents of red snap- 
per (Lutjanus campechanus) caught along the Atlantic coast of the southeastern 
United States in 2017 and 2018. Prey items were identified by using a combi- 
nation of visual and DNA barcoding methods. n=number of stomachs analyzed. 
804 300-500 mm (n=59) 804 501-700 mm (n=35) 
0 
Se IS RS S.° 
EK 
SS EK Os PP 
Ss ev SS SK ‘SS 
SX 
KS 
es 
Figure 6 
of co-occurring predators within this 
ecosystem are necessary to elucidate 
competitive interactions between red 
snapper and other managed species in 
the region. Forage fish species, such as 
mackerel and anchovy species, that are 
extensively preyed upon by other fish 
species have recently been recognized 
as important ecosystem components 
and have been included in fishery man- 
agement plans in the region and in bor- 
dering states (MAFMC, 2017; Federal 
Register, 2021). In our study, however, 
no specific prey emerged as strong can- 
didates for management as potential 
bottom-up control mechanisms of popu- 
lation growth for red snapper in the 
region. 
Conclusions 
Our study addressed the critical need for 
detailed trophic information necessary 
to assess specific ecological effects of a 
rebuilding red snapper population along 
>701-900 mm (n=13) 
Generalized diet composition by size class and prey category, according to index of relative impor- 
tance (IRD) values based on examination of stomach contents of red snapper (Lutjanus campecha- 
nus) caught along the Atlantic coast of the southeastern United States in 2017 and 2018. Prey 
items were identified by using a combination of visual and DNA barcoding methods. The size 
classes of red snapper are 300-500 mm in total length (TL), 501-700 mm TL, and 701-900 mm 
TL. n=number of stomachs analyzed. 
