Herpetofauna na região da Pequena Central Hidrelétrica Ypê, na região sul de Goiás

Abstract

The objective of this work was to determine the herpetofauna composition at the area of the Ypê Small Hydroelectric Power Plant (PCH Ypê), which is located between the municipalities of Acreúna, Santa Helena, Santo Antônio da Barra and Turvelândia, all of them situated in the State of Goiás, Brazil. The above-mentioned area is considered as being a remnant of the Cerrado Bioma, in southern Goiás, with its representative samples of riparian forest, semi-deciduous dry forest, ‘Cerradão’ (which is a more conspicuous type of Cerrado), and pastures as well. We compared the species richness and the number of sightings, among different phytophysiognomies and between rainy and dry periods of the year. Also, for each studied area, we tested and compared the sampling methods that were applied, as well as the endemisms related to such a rich Bioma. 15 campaigns were carried out at 12 points along the Verdão River. By using pitfalls (48,000 buckets/day), and also by using the time-limited active search (1,200 hours/observer), it was possible to record 75 species (37 amphibians and 38 reptiles - one Testudines, one Crocodylia and 36 Squamata: 14 lizards, one amphibenia and 21 snakes). The estimated richness, via Jacknife II, was 78 species and such a number is close to the expected richness for the region covered by the present study. A total of 4,115 sightings were recorded: 1,757(42.7%) individuals from 50 species in the Cerradão; 1,743(42.3%) individuals from 64 species in the riparian forest; 547(13.4%) individuals from 34 species in semi-deciduous dry forest, and 68(1.6%) individuals from 14 species in pasture areas. During the rainy season, with an average rainfall of 179 mm, we recorded 29 species, while in the dry season (35 mm of average rainfall), we recorded 23 species. Considering the sampling method, we can state that the time-limited active search was more efficient - 36 amphibian species and 22 reptile species. However, by pitfalls alone, it was possible to record 19 amphibians and 17 reptiles. As for all the amphibian registered species, we have found that 27% are endemic to the region, and when compared to Cerrado, they represent 9.2%. They are: Barycholos ternetzi, Dendropsophus cruzi, Dendropsophus rubicundulus, Ololygon centralis, Scinax constrictus, Physalaemus centralis, Physalaemus nattereri, Leptodactylus pustulatus, Chiasmocleis albopunctata e Pithecopus azureus. Regarding to the recorded reptiles (02 species - Bothrops moojeni and Xenopholis undulatus), we found 5.3% of endemism, which represents 1.9% for the total Cerrado biome. Through these data it was possible for us to perceive and evaluate the importance of such fragments for the conservation of herpetofauna, at the sampled region.