Ictiofauna De Riachos Das Cabeceiras Da Bacia Hidrográfica Do Alto Paranapanema

The Paraná River basin has about 600 fish species. In the Upper Paraná, 310 fish species were recorded, with 52 species were registered in the streams and headwaters of the Paranapanema River. The aim of this study was to characterize the stream fish communities in the Upper Paranapanema River basin. Samplings were conducted with electrofishing during the dry season in the year of 2014. The collection effort consisted of 30 streams stretches. As a result, 41 species of stream fish were recorded in the Upper Paranapanema River basin, distributed in 26 genera, 11 families and 7 orders. Thirty-nine percent of the species can be considered rare, 41% intermediate and 20% common. We captured approximately eight species by stream stretch and the estimated richness (Schao2) was 40 ± 6 species. Around 40% of the individuals had less than 50 mm in length. © 2016, Universidade Estadual de Campinas UNICAMP. All rights reserved.16

Stream Fish Fauna From The Tributaries Of The Upper Itapetininga River, Upper Paranapanema River Basin, State Of São Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The study area, which is located in urban and rural areas within the upper Paranapanema River basin, is undergoing several types of anthropogenic and non-anthropogenic impacts, such as chemical alterations, habitat disruption, and biological invasions. The aim of this study is to describe the fish faunal composition from tributaries of the Itapetininga River, upper Paranapanema River basin, state of São Paulo, Brazil. Herein, we include a list of 49 fish species, belonging to seven orders, 19 families and 35 genera, captured from September 2009 to November 2013. Thus, the present study fills part of the knowledge gap about the fish fauna from tributaries of the Paranapanema basin by adding data from small tributaries not studied so far. Moreover, our findings can help inform future conservational and/or management strategies within the upper Paranapanema basin. © 2016 Check List and Authors.12207/50981-7, FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo07/50982-3, FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo2012/09346-4, FAPESP, Fundação de Amparo à Pesquisa do Estado de São PauloFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Evidence of niche partitioning under ontogenetic influences among three morphologically similar siluriformes in small subtropical streams

Ontogenetic influences in patterns of niche breadth and feeding overlap were investigated in three species of Siluriformes (Heptapterus sp., Rhamdia quelen and Trichomycterus poikilos) aiming at understanding the species coexistence. Samplings were conducted bimonthly by electrofishing technique from June/2012 to June/2013 in ten streams of the northwestern state of Rio Grande do Sul, Brazil. The stomach contents of 1,948 individuals were analyzed by volumetric method, with 59 food items identified. In general Heptapterus sp. consumed a high proportion of Aegla sp., terrestrial plant remains and Megaloptera; R. quelen consumed fish, and Oligochaeta, followed by Aegla sp.; while the diet of T. poikilos was based on Simuliidae, Ephemeroptera and Trichoptera. Specie segregation was observed in the NMDS. Through PERMANOVA analysis feeding differences among species, and between a combination of species plus size classes were observed. IndVal showed which items were indicators of these differences. Niche breadth values were high for all species. The niche breadth values were low only for the larger size of R. quelen and Heptapterus sp. while T. poikilos values were more similar. Overall the species were a low feeding overlap values. The higher frequency of high feeding overlap was observed for interaction between Heptapterus sp. and T. poikilos. The null model confirmed the niche partitioning between the species. The higher frequency of high and intermediate feeding overlap values were reported to smaller size classes. The null model showed resource sharing between the species/size class. Therefore, overall species showed a resource partitioning because of the use of occasional items. However, these species share resources mainly in the early ontogenetic stages until the emphasized change of morphological characteristics leading to trophic niche expansion and the apparent segregation observed