Abstract:

Objective: To detect the species of larval trematodes (cercariae) in Melanopsis praemorsa snails from 5 different fresh water bodies in Palestine. Methods: A total of Melanopsis praemorsa snails were collected from different fresh water bodies from October, 2008 to November, 2010. Cercariae in Melanopsis praemorsa were obtained by lighting and crushing methods. The behavior of cercariae was observed using a dissecting microscope. Results: Three different species of larval trematodes were identified from Melanopsis praemorsa snails collected only from Al-Bathan fresh water body, while snails from other water bodies were not infected. These species were a microcercous cercaria, xiphidiocercaria, and a brevifurcate lophocercous cercaria. These cercariae called Cercaria melanopsi  palestinia I, C. melanopsi palestinia II and C. melanopsi palestinia III  have not been described before from this snail in Palestine. The infection rate of Melanopsis praemorsa collected from Al-Bathan fresh water body with these cercariae was 5.7%, while the overall infection rate of snails collected from all fresh water bodies was 4.3%. Details are presented on the morphology and behavior of the cercariae as well as on their development within the snail. Conclusion: These results have been recorded for the first time and these cercariae may be of medical and veterinary importance