الفهرس 
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Abstract
In the present study which was carried out in Beherira province, 29041 snail were collected from 5 different lacalities. These snails included Pulmonata, Prosobranchia and Bivalves. The Pulmonata snails were represented by Biomphalaria alexandrina, Bulinus contortus, Bulinus dybowski, Bulinus innesi, Planorbis philippi, Physa acuta, Lymnaea cailliaudi, Lymnaea alexandrina and Helisoma duryi. Prosobranchia snails were represented by Cleopatra bulimciides, Cleopatra cyclostomoides, Melania tuberculata Vivipara unicolor, Neritina nilotic and Lanistes bolteni. Also this study showed the appearance of a new unclassified snail.
The seasonal incidence of snails was high in spring 8853 (30.49%) followed by autumn 7487 (25.78%) and winter 6985 (24.05%) and decreased in summer 5716 (19.68%).
The factors affecting the snails populations were studied, like water temperature, food, light, depth of water and Hydrogen ion concentration anda competition phenomena in which, it was found that Helisoma duryi was only found in (Augast) in Abo El-Matamir district and the same month showed the lowest incidence of both Biomphalaria and Bulinus.