Stream quality and benthic macroinvertebrate diversity in the badeye area logone occidental province, southwestern chad.

The aim of this study of benthic macroinvertebrates in the south-western Canton Badeye in Chad was to determine their population structure in relation to the physicochemical quality of the water in the Man baptem tributary. A total of 4012 benthic macroinvertebrates in 38 families were identified and counted. Arthropods were the most diverse, with 35 families, and the most abundant (92.32%) of the total, followed by Molluscs (6.65%) and Annelids (1.02%). Insects predominated at all sampling stations (89.40%), followed by Gastropoda (6.75%), Malacostraca (2.85%), Achaete (0.57%) and Oligochaete (0.45%). The preponderance of the Chironomidae, Psychodidae and Physidae families in station A3 implies that the water at this station is of poor quality compared with the other 3 stations. The Shannon-Weaver and Piélou indices are higher at station C3, confirming some of the physicochemical parameter values at this station. Overall, the 4 sampling stations are diverse. The abundance of certain benthic groups such as Chironomidae Diptera in the Man baptem tributary shows that this watercourse is subject to anthropogenic disturbance.