author(s)
Fadéby Modeste Gouissi, Koudjodé Simon Abahi, David Darius Adje, Wilfrid Auguste Gbenou and Midogbo Pierre Gnohossou

abstract
Given the intensive use of pesticides, strong urbanization and population explosion, rivers have become a receptacle of solid and liquid waste causing ecotoxicological risk. This study aims to characterize the biodiversity of macroinvertebrates inthe Mékrou River in order to determine the parameters influencing their distribution. The physico-chemical parameters were measured by standard methods while the inventory of macroinvertebrates was done by using a surber net of a 500 -µm mesh and an area of 1/20 m². Data were collected at eight stations during floods. We used principal component analysis and canonical correspondence analysis to realize the abiotic typology of the stations and to correlate the biotic and abiotic data. Taxonomic richness, abundance and the observation frequency were used to describe the macroinvertebrate community. Apart from phosphate, other physicochemical parameters have values that are relatively compatible with aquatic life. The captured macrofauna is composed of 4747 macroinvertebrate individuals belonging to 26 families, 13 orders and 04 classes. The community is largely dominated by Insects constituting 94.88% of the total richness. Worms represent 3.14% of the total richness. Molluscs and Arachnids were the most marginal classes of the population. Diptera were the most abundant order and Chironomidae were the most prominent family. The predominance of Diptera, especially Chironomidae at the expense of Ephemeroptera and Trichoptera, would probably reflect the poor quality of the waters of Mekrou River. The predominance of Diptera, especially Chironomidae at the expense of Ephemeroptera and Trichoptera, would probably reflect the poor quality of the waters of the Mékrou River. The correspondence established between the families and the physicochemical parameters indicated that the distribution is influenced by the temperature, the conductivity, the TDS, the phosphates and the transparency.