Comparative diets of sympatric batoid elasmobranchs in the Gulf of Oman

Abstract

Documenting the interactions and mechanisms of coexistence among predators is important for understanding their ecological roles in food webs. Here, we examined the diet and trophic relationships of 6 demersal batoids coexisting in the Gulf of Oman by analyzing stomach contents. There were significant differences in diets among the batoid species, suggesting differential preferences. Diets of Gymnura poecilura and Torpedo sinuspersici were similar and consisted mostly of teleost fishes. In contrast, Brevitrygon walga and Rhinobatos punctifer mostly ate crustaceans. The diets of Maculabatis randalli and Pastinachus sephen were diverse and included crustaceans, teleosts, polychaetes, bivalves and echinoderms. The differences in diet among these batoids may be related to morphological differences in feeding structures and to differences in behavior, which could explain their diversity and coexistence in the Gulf of Oman.