Feeding ecology of the catfish Ictalurus punctatus (Siluriformes: Ictaluridae) in a reservoir in Northeast Mexico

Resumen

Objective: To determine the main food of the catfish according to seasonal variability and the sex of the
organism in the Venustiano Carranza Dam, Coahuila, Mexico.
Methodology: In total, 143 catfish stomachs from different seasons were examined. In the analysis of the stomach content, the detected organisms were determined until the taxonomic order rank. The seasonal and sex feeding variability were also analyzed. The Relative Importance Index and the Alimentary Index were applied. Non-parametric tests were carried out to compare stomach content between seasons and sexes.
Results: The total annual trophic spectrum for catfish consisted of 13 items, of which only the order Ephemeroptera was categorized as a frequent food. In the winter season the catfish consumed significantly more food compared to the other seasons, but there was no difference in the amount consumed by females and males (p>0.05).
Implications: This information is relevant to highlight the importance of the biological integrity of the terrestrial site which surrounds the reservoir as a source of food for the catfish.
Conclusions: Catfish channel in the Venustiano Carranza Dam is a generalist species (13 alimentary items). There was a difference in food consumed during the different seasons of the year. However, there was no difference between the sexes.