Community structure of molluscans in River Nile and its branches in Assiut governorate, Egypt

The present work aims to survey the benthic mollusc communities in River Nile and its branches in Assiut governorate, Egypt. Twenty-six species were recorded from the collecting sites during the period from March 2010 until March 2012. These species belong to fifteen families; eleven families of Gastropoda and four families of Bivalvia. The constant species in this survey were five species: Cleopatra bulimoides, Lanistes varicus, Lanistes carinatus, Melanoides tuberculata and Caelatura aegyptiaca. The accessory species were seventeen species: Mutela rostrata, Pila wernei, Sphaerium sp., Pila ovata, Bithynia connollyi, Lymnaea natalensis, Corbicula fluminalis, Theodoxus niloticus, Unio teretiusculus, Bellamya unicolor, Hydrobia aponensis, Pseudosuccinea columella, Valvata nilotica, Biomphalaria alexandrina, Bulinus truncates, Physa acuta and Gabbiella senaariensis and the accidental species were four species: Helisoma duryi, Succinea cleopatra, Corbicula fluminea and Gyraulus ehrenbergi. The species richness and diversity of molluscan community reach the maximum level in spring and summer months.