Hábito alimentar de anfíbios anuros do estado do Pará

Abstract

Days the feeding habits of 6 species of anuran amphibians from Pará State were studied by analyzing the stomach contents of specimens from the Herpetological Collection of MPEG. The goal is to contribute to the knowledge of the natural history of the anuran fauna of the region. The material examined consisted of preserved specimens, mostly from the Carajás region. The methodology of stomach contents analysis consisted of ventral dissection of the animals and analysis of the ingested material under the stereomicroscope, involving the identification (to the order level) and the measurements of size, weight and number of prey items. Of 205 specimens sampled (from 17 species), only 96 had any contents in their stomachs, so that 6 species had sufficient data for a preliminary diet description, with 14 specimens sampled from each species on average. The species of the Hylidae family, Hyla multifasciata, Phyllomedusa hypocondrialis, Phrynohyas venulosa and Osteocephalus taurinos, which have arboreal habits, had a wide variety of arthropods in their stomachs, with those of the orders Orthoptera, Coleoptera, Hemiptera, Lepidoptera (larvae) and Araneae being the most important, together constituting about 70% of the total mass of prey ingested per stomach, on average. On the other hand, the two ground-dwelling, leaf foraging species, Physalaemus ephippifer (Leptodactylidae) and Dendrobates galactonotus (Dendrobatidae) fed primarily on ants and termites (Hymenoptera and Isoptera, respectively), which together accounted for about 70% of the total prey mass ingested. The large number of specimens with empty stomachs may have been due to the fact that they were reproductively active at the time of capture, when they normally use energy reserves and decrease their feeding activity. Increasing the number of specimens and species examined should emphasize the relative importance of arthropod fauna for the different groups of anuran amphibians. The results presented here further suggest the importance of amphibian communities in food chains through their presumed effect on invertebrate populations.