The diet of Lithobates zweifeliwas studied by means of stomach flushing in a seasonal river of Morelos, Mexico.Diet was analyzed by season (wet and dry), development stages and by sex. Fooditems were classified by their habits in terrestrial or aquatic prey, and determinedto order, family, genus and sometimes to species. The diet of L. zweifelicomprised 102 nutritional components, mainly land habits insects. Hemiptera(Cicadellidae), Lepidoptera (Noctuidae) and Megaloptera (Corydalus texanus)had the highest values of ingestion and frecuence in the diet. We found 54 nutritionalcomponents in the dry season, and 84 in the rainy season. The estimated amplitudeof trophic niche by the Levin's method revealed low values in both seasons.Diet was constituted by 63 nutritional components in females, 55 in males and49 in juveniles. A Chi-squared test showed not significant differencesin the diet by development stage, sex, and season. The overlap of the trophicniches estimated by the MacArthur and Levin index revealed low value in sexand season combinations. The floating and riparian vegetation as insects' habitis important for the feeding of L. zweifeli.
