Original paper

Cyanobacterial taxa of the Senegal River system (northern Senegal, West Africa)

Berger, Céline Couté; Ba, N'Gansoumana; Gugger, Muriel

Abstract

Planktonic cyanobacteria were collected in the Senegal River system of northern Senegal at the end of the dry season in May 2002. 17 sites including tributaries, lakes, swamps and dams were sampled in order to identify cyanobacteria and to determine their diversity in this area. 79 different species belonging to the orders of Chroococcales, Nostocales, Oscillatoriales and Stigonematales composed cyanobacterial populations in this region. Chroococcales contained 23 taxa with 15 colonial and 6 solitary morphotypes. Oscillatoriales were represented by 33 taxa, 20 with solitary trichomes and 13 with solitary filaments or several trichomes contained in one unique sheath. Nostocales were composed of 22 taxa and Stigonematales by only one. Thus, filamentous forms represented 70 percent of the populations studied and coccoid forms only 30. Nine of the species described in this study belong to the potentially toxic taxa.

Keywords

africasenegal river systemcyanobacteria