ROTIFERA OF SOME LAKES IN THE FLOODPLAIN OF THE RIVER NIGER (IMO STATE, NIGERIA) .2. FAUNAL COMPOSITION AND DIVERSITY

The rotifer fauna of thirteen freshwater habitats in the lower Niger delta is commented upon. A total of 207 species of monogonont rotifers is recorded. The most diverse genus is Lecane with 59 species. Ten species appear to be endemic to the lower Niger delta, another 3 are restricted to Central and/or West Africa. Eleven taxa had ranges encompassing the Oriental and African regions, and six occur both in America and the study region. Three of the latter may represent recent introductions to the African continent. Two lakes (Iyi-Efi and Oguta), with 136 and 124 species on record, rank among the richest rotifer environments ever studied. It is hypothesized that (sub)tropical floodplains are the world's richest habitats for rotifers.