Dynamic of fish trophic guilds in the plateau-plain gradient in the Paraguay River, Northern Pantanal

This study aims to evaluate the dynamics of fish trophic guilds according to the longitudinal gradient of the Paraguay River, northern Pantanal, Brazil. Three river segments were sampled: plateau, confluence and plain. These segments have different physical and biological characteristics, with high water flow in forest areas in plateau and slow flow in meanders, with Pantanal typical vegetation. In total, 26,542 individuals distributed in 130 fish species were collected. The sampled species were characterized in seven trophic guilds. From the seven trophic guilds identified, only three were statistically related to the type of the environment; herbivores were more abundant in the plateau, piscivores in the confluence, and invertivores in the plain. According to values of corrected Akaike Information Criteria, the environmental variable that best explains the abundance of piscivorous fishes in the segments sampled in the Paraguay River was water transparency. For herbivores, the model that explained the variation in abundance was composed by temperature, altitude and dense forest proportion. The variable altitude best represented the abundance of invertivores. Water transparency, temperature, altitude, river width and dense forest proportion were determining factors for the distribution of piscivorous, herbivorous and invertivorous fishes as a response to an environmental gradient that meets its ecological requirements. Understanding the trophic relationships is fundamental for management actions, contributing to the maintenance of ecosystem services of different species. Therefore, future research must be taken into account regarding management and ecological relationships

Geographic range extension of Elachistocleis corumbaensis Piva, Caramaschi & Albuquerque, 2017 (Anura, Microhylidae) with new records in ecotonal zones in the state of Mato Grosso, Brazil

Elachistocleis corumbaensis was documented in 2017 in the central region of the Brazilian Pantanal and no other record of the species has since been reported. In this study, we report on the extension of the geographic range of E. corumbaensis based on 4 new records found in the riparian forests of the Paraguay River, in the state of Mato Grosso. Of these, 1 specimen was collected in a protected area in the Pantanal. We also report on the presence of this species in the ecotones between the Pantanal, Cerrado, and Amazonia, which suggests that E. corumbaensis is associated with seasonally flooded forests but more widely distributed in western Brazil than previously reported

New records amplify the geographical distribution of Rondonops biscutatus Colli et al., 2015 (Squamata, Sauria, Gymnophthalmidae) into the Paraguay river basin, Mato Grosso, Brazil

Rondonops biscutatus is a gymnophthalmid litter-lizard which occurs in the Amazon rainforests and the transitional areas between Amazonia and Cerrado. This species’ distribution is strongly biased by a lack of data, possibly because it was recently described, small-bodied, and living in cryptic habits. Here, we present occurrence data of six specimens from four locations in transitional areas between forests in Amazonia and Cerrado (central Brazil), in the upper Paraguay River, at the northern end of the Pantanal, midwestern Brazil. We expand the distribution of this species 507 km east from its original range.

Núcleos de Ensino da Unesp: artigos 2008

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq