Espectro trófico del bagre Ictalurus punctatus (Silurifomes: Ictaluridae), en la presa Lázaro Cárdenas, Indé, Durango, México

Having the objective of determining their trophic spectrum and their variations within a year, the contents of 240 stomachs of Ictalurus punctatus (Rafinesque, 1818) were analyzed from 2006 to 2007. The items of the stomach contents were determined to the order level. The data was analyzed by different quantitative and qualitative methods. The most frequent orders were Perciforms and Atheriniforms corresponding to forage fish, along with green algae of the Charales order. Also, seven orders of invertebrates were found:  Schizodonta, Odonata, Himenoptera, Orthoptera, Hemiptera, Homoptera and Scorpionida, and two orders of plants: Poales and Fabales. The Perciform order made up almost half of the total weight of the stomach contents, followed by the Atheriniform and the Charales orders. The greatest number of empty stomachs showed up during summer and winter, while the greatest number of filled-up stomachs was found during the spring season. The quantity of food consumed during winter time was significantly lower than the amount consumed during all other seasons. The kind of food consumed during the spring, summer and autumn was mainly fish, while algae were preferred during the winter season.