Trophic interactions between the 11 most abundant demersal fish species on the Pacific coast of central Mexico

Abstract

We describe the diet, feeding strategy, and trophic interactions between the 11 most abundant demersal fish species on the Pacific coast of central Mexico during both the warm and cold seasons. A total of 4,547 stomachs were collected, with 1,921 empty stomachs being discarded. According to the stomach content analysis, 95 prey items were identified and grouped into 70 food categories belonging to crustaceans, mollusks, fish, polychaetes, and echinoderms. The Smith index value and high prey diversity indicated that the 11 fish species exhibited a generalist opportunistic feeding strategy in both survey seasons. Low values of dietary overlap were recorded, and only a few significant cases of dietary overlap were found in the interaction between some rays (Urotrygonidae) and flatfish species (Pleuronectiformes). The availability and abundance of prey resources in the environment and the generalization of niche breadth allows the demersal predator community of the soft shallow bottoms to coexist without any evident competition for trophic resources.

Keywords

• trophic interactions
• demersal
• fish
• niche breadth
• stomach contents