<b>Periphytic cyanobacterial community from Segredo and Iraí reservoirs, State of Parana, Brazil</b>- DOI: 10.4025/actascibiolsci.165

Abstract

In order to evaluate spatial-temporal distribution of periphytic cyanobacterial community, as well as the influence of abiotic factors on these organisms, samples were collected in two reservoirs: Segredo and Iraí, located within the Iguaçu river basin, State of Paraná. Samplings were collected in summer (April) and winter (September), 2002, in upper, intermediary and lower regions. A total of 66 cyanobacterial species were registered, with fifty species occurring in Iraí Reservoir and thirty-eight in Segredo Reservoir. Iraí showed higher values of cyanobacteria density (25 to 101 x ind 10³ cm^-2) when compared with Segredo (1 to 14 x ind 10³ cm^-2). We believe that cyanobacteria composition and density resulted from several factors, with preponderance of the effects of abiotic variables differences (nitrogen, phosphorus and temperature) along the longitudinal axis and along the different seasons, as well as the morphometric and hydrodynamic effects.