Ichthyofauna of the Cachoeira de Sao Roberto and fishes of lower Preto River, upper Parana River basin, Brazil

Rheophilic environments typically houses fish species with specific ecological requirements. Thus, the suppression of these environments can lead to damaging impacts to local and regional fauna. In this work the ichthyofauna of the Cachoeira de Sao Roberto was inventoried, with a historical review of fish collected in the lower Preto River basin. The sampling sites included two reaches (named R1 and R2): R1 in the Cachoeira de Sao Roberto and R2 refers to two km upstream. The fishes were sampled bimonthly during one year (April 2013 to February 2014) using small and dip nets. Voucher specimens were catalogued in the Fish Collection of Departamento de Zoologia e Botanica do Instituto de Biociencias, Letras e Ciencias Exatas, Universidade Estadual Paulista Julio de Mesquita Filho', campus de Sao Jose do Rio Preto, SP. (DZSJRP). Historical records from lower Preto River basin were composed by fish species sampled downstream of spillway of the dam in the municipality of Sao Jose do Rio Preto, SP, using the database of fish collection of DZSJRP. The ichthyofauna of the sampled reaches was composed by 53 species, distributed in 16 families and seven orders. The greatest richness was found in the upstream site (R2) with the presence of Aphyocheirodon hemigrammus and Myleus tiete, two Brazilian threatened fish species. Chao index suggested the occurrence of 64 species for the inventoried reaches. Considering all portion of lower Preto River basin, including historical records, 69 species were found, four of these species have not described yet. The present study highlights the importance of inventories in rheophilic environments, which usually includes sensitive, threatened, and species with restricted distribution. Besides that, inventories can provide technical data to support decisions about potential environmental impacts helping with the management and conservation of fish fauna.