Composition and Spatio-seasonal dynamics of periphytic microalgae of the Banco River

The spatio-seasonal dynamics of periphytic microalgae from the Banco River were analyzed from samples collected monthly from July 2020 to June 2021 (grouping four climatic seasons).A total of 131 taxa of specific and infraspecific rank were identified.These taxa are divided into 44 genera, 26 families, 17 orders, 9 classes and 6 phyla.Euglenophytes with 54 taxa, or 41.22%, predominate the taxonomic richness.This phylum is followed by Chlorophytes (31.29%),Heterokontophytes (12.97%),Cyanobacteria (10.68%),Dynophytes (2.29%) and Rhodophytes (1.52%).The distribution of algae classes in the different stations of the Banco River shows that the most important group of periphytic microalgae is that of Euglenophyceae which represent 41.22% of the taxa followed by Zygnematophyceae (17.55%),Chlorophyceae (13.74%),Bacillariophyceae (11.45%), of Cyanophyceae (10.68%),Dinophyceae (3.81%) and Rhodophyceae (1.52%).The Mediophyceae and the Xanthophyceae form the least represented class, i.e. 0.7% each.Station B1 constitutes the environment with the highest periphytic biomass (477x10^4 Cell/L).Dominant taxa such as: Euglena sanguinea, Euglena sociabilis, Euglena splendens, Euglena viridis, Trachelomonas caudata, Trachelomonas hispida, Phacus curvicauda are characteristics of disturbed environments.The values of Shannon's diversity index (H') and Equitability (E) vary between 1.77 (at station B4 during the short rainy season) has 3.80 bits/cells (at station B1 during the short dry season) And between 0.82 (at station B4 during the main rainy season) and 0.96 (at station B1 during the Composition