Diatoms from distinct habitats of a highly heterogeneous reservoir, Billings Complex, southeastern Brazil

ABSTRACT A diatom survey was carried out in the largest reservoir of the city of São Paulo. Twenty-four phytoplankton, 15 periphyton, and 12 surface sediment samples covering a gradient of trophic states were collected in 2009 and 2010. Overall, 67 taxa were sampled (60 species and varieties and seven identified at the genus level). Four species are new records to Brazil (Stephanodiscus minutulus, Fragilaria aquaplus, F. perminuta and Ulnaria ferefusiformis), and beyond those, six others are new records to the State of São Paulo. Periphyton accounted for the highest number of species (68.6%) and exclusive taxa (21). The eutrophic and natural mesotrophic regions presented the highest number of species (46 and 41 taxa, respectively), contrasting with the hypereutrophic and artificial mesotrophic regions (22 taxa each). Present findings highlight that the local biodiversity can be directly influenced by the type of habitat analyzed, and different habitats should be included for improving the knowledge of local biodiversity.