Cyanobacteria from different types of lakes ("salina", "salitrada" and "baía") representative of the Pantanal da Nhecolândia, MS, Brazil

Considering the ecological importance of cyanobacteria and the scarcity of more precise information about these organisms in the different aquatic systems of the Brazilian Pantanal, our aim is the study of the cyanobacterial flora in three lakes in the Pantanal da Nhecolândia region. The studied lakes are natural water bodies and are shallow (maximum depth 1.1 m), rounded and present different limnological features mainly regardin to the pH and salinity. The samples were collected in the dry and rainy seasons, during 2004-2007. Twenty one species of cyanobacteria were identified. Oscillatoriales was the order with the highest species richness (24% of the total of the identified species), followed by Synechococcales, Pseudanabaenales, Chroococcales and Nostocales, each one contributing with 19%. The lake "Salina do Meio" presents extreme environmental conditions and was the highest species richness system for cyanobacterial (13 species - 62%). In this lake, blooms of Anabaenopsis elenkinii Miller were observed, mainly during the dry season. The lakes "Salitrada Campo Dora" (9 species) and "Baía da Sede Nhumirim" (9) presented equals species richness, but the floristic composition was distinct probably due to their different limnological conditions. All the species were referred for the first time to the Brazilian Pantanal.

biodiversity; cyanobacteria; lakes; Pantanal