This book is part of an earlier publication series on "THE CONGO FAUNA" in 2018. It concerns scientific research carried out on Macroinvertebrates collected on the surface (Pelagic) from the waters of ponds located in collapsed areas known as "Nkumbikumbi" and "Frères Franciscains" in the Commune of Muya in Mbujimayi.A total of 1,142 pelagic macroinvertebrate specimens were sampled and identified in 2016, including 483 in the dry season (2 classes, 5 orders and 8 families) and 659 in the rainy season (3 classes, 5 orders and 8 families).Calculation of the Shannon and Weaver diversity, Piélou equitability, Jaccard similarity and Hilsenhoff pollution tolerance or intolerance indices showed that the waters of these two hydrosystems are of poor ecological and biological quality.