Trophic interrelations in a beach seine fishery from the northwestern coast of the Yucatan peninsula, Mexico

The main trophic interrelations were analysed in 12 species which represent 93% of the total catch from a beach seine fishery developed in Celestún, Yucatán. The diet was determined based on monthly samples over 4 yr. Five different trophic guilds were found on the basis of feeding preferences: microcrustacean and polychaete feeders, piscivores, omnivores and herbivores. For microcrustacean feeders Orthopristis chrysoptera, Eucinostomus gula, E. argenteus and Opisthonema oglinum the diet is narrow with a large overlap between. For polychaete feeders, Arius felis, A. melanopus and Haemulon plumieri diet is broad with the higher overlap between the catfishes. Among piscivores, Bardiella chrysura and Harengula jaguana have a high overlap between them, but a lower one with other species from the community. Among omnivores Lagodon rhomboides has the broadest diet and is considered to be a generalist while Acanthostraceon quadricornis is a specialist having a very narrow diet and a lower value of overlap with the other species. Finally, Archosargus rhomboidalis is a herbivore with the narrowest niche breadth and lowest overlap. In addition to a description of diets and trophic inter‐relations, the results emphasize the importance to the beach seine fishery of the benthic food resources.