The survey is a floristic inventory of centric diatoms from the region to be flooded by the construction of the Salto Caxias hydroelectric power plant reservoir, in southeast Paraná State, Brazil. Planktonic sampling was carried out monthly, from March/97 to February/98. Nineteen infrageneric taxa were identified. Aulacoseira ambígua var. ambígua, A. granulata var. granulata, A. granulata var. angustíssima and Melosira varians being the most common taxa, occuring in 85% of the 171 samples studied. Aulacoseira agassizii var. agassizii and Melosira undulata var. normanii are new records for the State of Paraná, and Terpsinoe musica var. musica registered for the first time in freshwater environments in this state.
Bacillariophyta; centric diatoms; flora; Paraná State