Journal of Biology and Nature

Anthropogenic pressures are among the major drivers of aquatic ecosystem degradation, and Zygnematophyceae are considered reliable bioindicators for evaluating ecological changes in freshwater environments. The main objective was to determine the diversity of Zygnematophyceae and to characterise some dominant species in selected rivers of the city of Bamenda. Microalgae were collected from 16 sampling sites located along the wetland rivers of Bamenda between October and December 2023 using a plankton net. Physicochemical parameters were simultaneously measured. The collected Zygnematophyceae cells were identified, described and counted. The biological diversity indices and the abundance of these cells at each site were determined. The waters of the urban rivers of Bamenda exhibited slightly acidic to slightly alkaline conditions, with dissolved oxygen concentrations ranging from 1.98 to 6.54 mg/L. A total of 22 species and 10 genera of Zygnematophyceae, divided into 2 orders and 4 families, were identified. The families Desmidiaceae and Closteriaceae were the most diverse. Closterium acerosum, Closterium ehrenbergii, Closterium parvulum, Gonatozygon monotaenium, Micrasterias radians, Pleurotaenium ehrenbergii, Spirogyra ellipsospora, Spirogyra gracilis and Zygnema stellinum were the dominant species. Diversity indices were moderately high and varied significantly from one site to another. Zygnematophyceae were most abundant at site 1 (5335 ± 859 individuals/mL) and at site 6 (4190 ± 995 individuals/mL). These results contribute to knowledge of biodiversity in the urban rivers of Bamenda. They may support the management and monitoring of these rivers.