Affiliation: | Environmental Studies Centre 'Demetra' and F.I.Z.V., via dei Cochi 48/B, I-00133 Rome, Italy;and Museo Civico di Storia Naturale, piazza Aristide Frezza 6, I-00030 Capranica Prenestina, Rome, Italy,;Department of Biological Sciences, The Rivers State University of Science and Technology, P.M.B. 5080, Port Harcourt, Rivers State, Nigeria |