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El presente trabajo estudia la dieta de una población de Leptodactylus ocellatus de los Humedales de Zonda, San Juan, al oeste de Argentina. Se analizaron 35 estómagos, las presas fueron clasificadas y los individuos se midieron en ancho y largo para calcular su volumen con la fórmula de la esfera elipsoide; además, se estimó la frecuencia de ocurrencia y abundancia. Se calcularon índices de diversidad, de similitud, amplitud de nicho e importancia relativa (IRI). Los presas mas importantes fueron: Hymenoptera, Anura, Coleoptera. Las presas con mayor porcentaje de presencia fueron los Hymenoptera Formicidae que representaron el 22,4%. No se encontró una relación significativa entre el ancho de la boca del depredador y el tamaño medio de la presa. La dieta observada en ambos sexos resultó similar.

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The American bullfrog Lithobates catesbeianus has been introduced around the world, with invasive populations reported from almost all South American countries. A population of this species was introduced in the Calingasta department of San Juan province, which is an arid environment in western Argentina. This work provides information on the dietary composition of an invasive population of L. catesbeianus, and compares the degree of dietary overlap between adults and juveniles. Stomach contents of 169 bullfrogs (82 adults and 87 juveniles) were analysed. Adults consumed 40 prey taxa and Hymenoptera (Insecta) was the most numerous prey item (41.8%), followed by Araneae (13.6%) and Aeglidae (13.4%). Juveniles consumed 29 prey taxa and Hymenoptera constituted the highest percentage in prey number (77.2%). The trophic overlap niche index at the same level shows a value of 0.64 overlap in dietary community between adults and juveniles of this bullfrog. Aeglidae was volumetrically the most important trophic item (25.4%), followed by Anura (25.02%). Our results showed that cannibalism in bullfrogs is more common than the consumption of native anurans, coinciding with that reported in other populations of introduced bullfrogs. The high similarity in the diets of both size classes and the association between the size of the predator and prey suggest that the impact caused by bullfrogs throughout their ontogeny is high and probably has an impact on their prey. Freshwater crabs are the main items in the diet of Lithobates catesbeianus in other introduced populations and are usually the most conspicuous at our study site. The crabs in freshwater ecosystems are part of the lowest trophic level in the food chain. The major threats to the southern region's freshwater crabs include deforestation, farming and exotic species. Lithobates catesbeianus has a generalist diet and high overlap between adults and juveniles.

A new species of bufonid frog, Rhinella bernardoi sp. nov., belonging to the granulosa group, is described from moderately high elevation (1400 m) at Ischigualasto Provincial Park, San Juan, Argentina. The morphology of the new species is compared to and diagnosed from other closely related species of the same group (R. bergi, R. fernandezae, and R. granulosa). We also describe the osteology of the skull and the vertebral column of the new species and present data on its geographic distribution and natural history.