Composición de la dieta de Ictalurus meridionalis (Gunther, 1864) (Actinopterygii, Ictaluridae), en la cuenca media del río Grijalva, Chiapas, México

Abstract

El presente estudio se realizó con organismos de Ictalurus meridionalis que corresponden a las capturas comerciales de dos cooperativas pesqueras. Con el análisis de contenido estomacal se determinaron nueve grupos presa, el mayor porcentaje de Frecuencia de Ocurrencia (FO) de los componentes alimenticios correspondió al grupo presa restos de insectos (24.40%), seguido cercanamente por restos de peces (22.02%). Respecto al Índice de Valor de Importancia relativa (IVIr) el mayor porcentaje lo presentaron los restos de peces (IVIr 26.29%), seguido de restos vegetales (IVIr 22.43%). Asímismo se estimó el Índice Intestinal (II) para expresar el hábito alimenticio de la especie, se obtuvo que en general Ictalurus meridionalis es un pez omnívoro el cual exhibe una tendencia al aumento del nivel trófico con el aumento de tamaño corporal, en tallas menores a 25 cm tiene una dieta herbívora pero con un alto consumo de insectos y a tallas mayores a 40 exhibe una dieta omnívora con tendencia piscívora.

The present study was conducted with Ictalurus meridionalis organisms that correspond to the commercial catches of two fishing cooperatives. With the analysis of stomach contents, nine groups were determined prey, the highest percentage of Occurrence Frequency (FO) of the food components corresponded to the insect prey group (24.40%), followed closely by fish remains (22.02%). Regarding the Relative Importance Value Index (IVIr), the highest percentage was presented by fish remains (IVIr 26.29%), followed by vegetable remains (IVIr 22.43%). Likewise the Intestinal Index (II) was esti- mated to express the food habit of the species, it was obtained that in general Ictalurus meridionalis is an omnivorous fish which exhibits a tendency to increase the trophic level with the increase in body size, in smaller sizes at 25 cm it has a herbivorous diet but with a high consumption of insects and at sizes greater than 40 it exhibits an omnivorous diet with a piscivorous tendency.