Red snapper (Lutjanus campechanus) diet in the North-Central Gulf of Mexico on Alabama artificial reefs

Red Snapper, Lutjanus campechanus, is a highly exploited reef fish in the Gulf of Mexico (Gulf) that occupies both natural hard-bottom and artificial habitats. Despite its importance, little is known about its feeding habits. Toward this end, we examined the size-specific diet of red snapper collected for stomach content analysis from artificial reefs in the north-central Gulf of Alabama between May 1999 April 2000. Thirty-nine to 86 stomachs per month were removed and prey items were identified to the lowest possible taxonomic level. The relative contribution of prey items was determined using percent composition by weight, percent composition by number, percent frequency. of occurrence, and index of relative importance (IRI). Results suggest that snapper are feeding on organisms not associated with reefs, such as mantis shrimp and portunid crabs. Diet changes seasonally, with crabs being most important (38% and 43% by IRI) in summer and fall, while mantis shrimp dominate in winter (42% IRI). Pelagic zooplankton was the greatest by percent weight in the diet in spring (60% IRI). Fish also contribute to each season, but they are not the principal prey items in any season (28% - 30% IRI). These diet data ultimately will be used in combination with a bioenergetics model to estimate prey demand of snapper on Alabama artificial reefs.