Characteristics and Diversity of Cyanobacteria in Periphyton from Lentic Tropical Ecosystem, Brazil

This study aimed to perform the taxonomic survey of the species of periphytic Cyanobacteria in a lentic tropical environment, seeking to contribute to the knowledge on biodiversity and their distribution. This study was conducted at the Samambaia Reservoir, which is located at Federal University of Goiás, Goiania, Central West region of Brazil. In general, the water of the Samambaia Reservoir is characterized as more turbid and the increased biochemical oxygen demand as well as a higher concentration of coliforms in the rainy season. Twenty six samples were collected, ten in the dry season (09/2010 and 11/2010; 07/2012) and ten in the rainy season (01/2011 and 03/2011; 01/2013). Periphyton was collected from stems of aquatic plants (Cyperaceae), which were in the marginal area of the reservoir. With the floristic survey, 38 taxa of Cyanobacteria were identified in periphyton of the Samambaia Reservoir. Phormidium (family Phormidiaceae) and Aphanocapsa (Merismopediaceae) are among genera with the highest species richness. Regarding morphological types, many species of filamentous cyanobacteria were identified, followed by colonial taxa. In relation to the frequency of occurrence and the seasonal period, 14 taxa were classified in the rare category, 12 in common category and 12 in constant category. Regarding the seasonal period, Cyanophyceae were the greatest wealth in the rainy season (97.4%).