AN OUTLINE ON LATERAL FISH MIGRATIONS WITHIN THE CENTRAL DELTA OF THE NIGER RIVER, MALI

The lateral migration of fishes was studied during one entire flood cycle (1991) in a typical floodplain sector of the Central Delta of Niger at Batamani, Mall. The intensity and temporal course of migrations, as well as the species and size composition of migrants, were found to be correlated with the hydrological regime (river and floodplain water levels, direction and velocity of water flow in a temporary canal). Four different types of migratory patterns were described and their typical representatives indicated. The significant role of the river as a spawning site and that of the flood plain as a nursery for most locally important fishes was also accentuated.