Abstract

Descriptions of the diet composition, trophic positions, and diet overlap among co-occuring species can provide a framework for management of these species and important habitat resources, particularly for ecosystem-based fisheries management. Collected from the shelf-edge banks of the northwestern Gulf of Mexico from 2015 through 2017, the diets and trophic ecology of 3 Lutanidae species, red snapper (Lutjanus camprechanus), blackfin snapper (Lutjanus buccanella), and vermilion snapper (Rhomboplites aurorubens), were examined. Stomach contents were identified to determine the diet composition and diet overlap among species. Stable isotopes were used to identify the isotopic niche and overlap among species as a correspondent to define trophic niches. Analysis has yet to be complete, however, some general trends have been noted. Stomach content results have shown a higher contribution of small crustaceans in vermilion snapper compared to red snapper and blackfin snapper. Red snapper and blackfin snapper showed higher contributions of fish and crabs. Stable isotopes results indicate that vermilion snapper feed on a different carbon source than do that of red snapper and blackfin snapper. Red snapper and blackfin snapper were more similar in nitrogen ratios, indicating that they exist in similar trophic levels and that is potential for interspecific competition for prey resources.

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