The building of hydroelectric dams has consequences on the ecological conditions of ecosystems, such as the regression or disappearance of certain species that have a benthic entomophagous diet or a proliferation of omnivorous and planktivorous species. The study of fish feeding can provide data not only on the presence of prey, but also on the abundance and availability of trophic potential. In view of the new hydroelectric development project on the Bandama River, this study proposes to examine the diets of Synodontis bastiani, S. schall and S. punctifer that are captured in the area. Stomachs were collected and contents examined from fish caught monthly between November 2019 and October 2020 using gill nets in the N'Dènou locality. A total of 417 fish belonging to S. bastiani, S. schall, S. punctifer were examined. The food spectrum of the studied species is wide and diversified. It is mainly composed of Macrophytes, Insects, Worms, Mollusks, Zooplankton, Crustaceans. These species are all omnivorous with a benthophagous tendency. No difference was observed in the diet according to the size.

Aims: We are investigating benthic macroinvertebrates in two rice-growing dams and assessing their pollution levels. Place and Duration of Study: Nanan and Zatta Dams of Yamoussoukro in Côte d’Ivoire from April 2021 to March 2022. Methodology: Samples were collected monthly with a Van Veen bucket and a dip net and the environmental variables measured. Results: The values of the physico-chemical variables show that the waters are warm and more mineralized at Nanan than at Zatta. The species richness is higher at Zatta with 75 taxa present against 42 taxa at Nanan. The population is globally dominated by insects at Zatta, but a strong representation of Molluscs is observed at Nanan. The abundance of Molluscs indicates organic pollution in the Nanan dam. The water pollution tolerance index between the two dams showed a predominance at Zatta, of the Ephemeroptera group which are polluo-sensitive organisms against a predominance at Nanan, of the Diptera group which are polluo-resistant. The Shannon index and the others indexes of the two sites confirm a clear water pollution in Nanan compared to Zatta. Conclusion: These results suggest that the Zatta dam is in better condition than the Nanan dam. However, these two dams must be bio-monitored.