Planktonic Radiococcaceae Fott ex Komarek of the Tigres Lake system, Britania, Goias State, Brazil

(Planktonic Radiococcaceae Fott ex Komarek of the Tigres Lake system, Britania, Goias State, Brazil) The family Radiococcaceae Fott ex Komarek (Chlorophyta) has not been intensively studied due to difficulties related to the identification and circumscriptions of its genera and species. The taxa of this family occur mainly in lentic systems. The present study surveyed the planktonic radiococcacean algae in the Tigres Lake system, in Britania, Goias State, Brazil. Subsurface samples were collected monthly between July/2008 and January/2009 comprising both dry (from July to September) and rainy seasons (from October to January) using a plankton net (25 mu m mesh) at 11 sites. A total of 17 taxa were found representing five genera, with Radiococcus (35 %) and Eutetramorus (29 %) being the most representative. The three most frequent taxa were Eutetramorus planctonicus (Korshikov) Bourrelly, Radiococcus fottii (Hindak) Koshikov et al., and Eutetramorus tetrasporus Komarek. Eight new taxa for Goias State were recorded.