Diet of Melanophryniscus paraguayensis (Anura: Bufonidae): an Endemic Species to Paraguay

NÚÑEZ, K; DURÉ, M. I.; ZÁRATE, G; ORTIZ, F; MENDOZA, M

Herpetological Conservation and Biology

Herpetological Conservation and Biology

Año: 2021 vol. 16 p. 251 - 258

1931-7603

Melanophryniscus paraguayensis (no common name) is anendemic toad of the central grasslands in the eastern region of Paraguay.Details about its natural history are poorly understood and it is categorizednationally as Vulnerable. This work describes the diet composition of thisspecies and the relationship between toad body size and the number and volumeof prey consumed. We analyzed the stomach content of 162 individuals, using thestomach flushing technique, after measuring and weighing them. For each preycategory, we calculated the volume, number, and frequency of occurrence, and weestimated the relative importance index (IRI) with these data. We alsoestimated the standardized Shannon Diversity Index and Levins Niche BreadthIndex for prey categories, and we analyzed the correlation between size of theanurans and prey size. Seventy-six individuals had identifiable content, whichconsisted of 1,357 prey classified into 16 categories, mostly at the orderlevel. Ants and mites were the prey taxa with the greatest contribution innumber and frequency and represent the most important prey based on IRI.Volumetrically, ants and beetles predominated. Ticks, spiders, springtails,flies, true bugs, wasps, termites, thrips, larvae and nymphs of insects,centipedes, crabs, and snails were occasional prey. The mean prey volumeconsumed by toads was positively correlated with toad snout-vent length. TheShannon and Levins índices showed that the composition of the diet was dominatedby a few groups of arthropods. This work demonstrates the importance of ants,mites, and beetles as food for M. paraguayensis, which is consistent withfindings for other species of the genus Melanophryniscus and of many species ofthe Bufonidae family.