Fitoplâncton de um reservatório eutrófico (lago Monte Alegre), Ribeirão Preto, São Paulo, Brasil

Abstract

The study aims at presenting the phytoplankton of a small eutrophic reservoir, located in the Southeast of Brazil, based in samples fortnightly collected from April of 1988 to March of 1989 from one station located at the centre of the limnetic region. Ninety three species were identified, 9 varieties, 5 taxonomic forms, 9 taxa were determined at generic level and 3 were listed in their respective classes, in a total of 119 taxa belonging to 9 taxonomic classes (13 Cyanophyceae, 55 Chlorophyceae, 15 Zygnemaphyceae, 14 Euglenophyceae, 5 Bacillariophyceae, 3 Xanthophyceae, 6 Chrysophyceae, 4 Cryptophyceae e 4 Dinophyceae). It was observed a considerable complexity in the floristic composition in the Lake Monte Alegre, as registered in relation to other tropical lakes and reservoirs, with a bigger dominance of the green algae (59%). The phytoplankton species was used as one of the aspects for the trophic characterization of the environment.