Diatomáceas cêntricas de rios na região de abrangência da usina hidrelétrica de Salto Caxias, PR, (Bacia do rio Iguaçu)

Abstract

Realizou-se o inventário florístico das diatomáceas cêntricas dos rios da região a ser inundada para construção do reservatório da Usina Hidrelétrica de Salto Caxias, localizado a sudoeste do Estado do Paraná. Amostras planctônicas foram coletadas mensalmente, em 15 estações de coleta, no período compreendido entre março/97 e fevereiro/98. Foram identificados 19 táxons infragenéricos. Aulacoseira ambígua var. ambígua f. ambígua, A. granulata var. granulata, A. granulata var. angustíssima e Melosira varians foram registradas em pelo menos 85% das 171 amostras estudadas. Aulacoseira agassizii var. agassizii e Melosira undulata var. normanii são citações pioneiras para o Estado do Paraná, assim como Terpsinoe musica var. musica é registrado pela primeira vez em ambientes continentais paranaenses.

Coscinodiscophyceae and Fragilariophyceae (Diatomeae) in the Iguaçu River, Paraná, Brazil

“…The population studied coincided with those described and illustrated by Contin (1990), Krammer & Lange-Bertalot (1991), Brassac et al (1999) and Guerrero & Echenique (2006). The smaller dimensions shown by Contin (1990, D: 8.60-12.35 μm) and Bertolli et al (2010, D: 7.11-13.43 μm) were not observed in the specimens of this study.…”

“…normanii are in agreement with the descriptions of Brassac et al (1999) for the state of Paraná and of Garcia (2009) for the state of Rio Grande do Sul. However, the cellular dimensions differ from those of the species found by Rosa et al (1994, D: 45.4 μm) for lakes in Rio Grande do Sul.…”

“…normanii differs from the typical variety by displaying radial striae with a spiral arrangement in the central region (Brassac et al 1999). Krammer & Lange-Bertalot (1991) Valves cylindrical, forming rectilinear chains, inconspicuous marginal spines connecting the valve faces.…”

“…The specimen found is similar to those of the dendroteres-group analyzed by Houk (1993, fig. 1-6); to the material identified as Orthoseira roeseana, collected by Brassac et al (1999, fig. 29) and Metzeltin et al (2005, pl. 2:1-3); and to the specimens illustrated by Krammer & Lange-Bertalot (1991: pl.…”

“…Subsequently, other studies of diatoms were conducted along the watershed. Ludwig & Flôres (1995;1997) conducted studies in rivers within the catchment area of the Segredo hydroelectric power plant, and Brassac et al (1999) studied the area around the Salto Caxias hydroelectric power plant, both identifying centric diatoms. Similar studies were conducted by Tremarin et al (2009a), in the Maurício River, and by Santos et al (2011), in the Salto Amazonas River and in an artificial lake in the municipality of General Carneiro.…”