Objective: To investigate other new species of cercariae encountered in Melanopsis praemorsa (M. praemorsa) snails collected from Palestine. Methods: A total of 1 100 M. praemorsa were collected from Al-Bathan water body, Palestine, from November, 2010 to November, 2011. Cercariae in M. praemorsa were obtained by emerging and crushing methods. Results: Other three new different species of cercariae have been identified from this snail. These species were Xiphidiocercaria (Cercaria melanopsi palestinia IV), Microcercous (Cercaria melanopsi palestinia V) and Longifurcate cercaria (Cercaria melanopsi palestinia VI). The infection rate ofM. praemorsa with these three different cercariae was (42.2%). Coinfection with Xiphidiocercariae and Longifurcate cercariae or Xiphidiocercariae and Microcercous cercariae has been noted and coinfection rate was 1.23% among the infected snails. The highest cercarial infection rate was in June (64.3%). No infected snails were found in September. It was also noted that infected snails attained a larger size than uninfected ones and all infected snails had a size between 17-22 mm (average 20 mm). Conclusions: Our studies imply that there are potentially more new species of trematodes in this area than were found until now. Due to the presence of infected M. praemorsa and may be species of other snails, water resources could be contaminated by the emerging new cercariae, consequently attack the local people directly via the skin or are transferred to them by metacercariae ingestion. More surveys are needed to identify the real prevalence of the trematodes both in human and animal hosts, and also to determine the range of snail hosts of the parasite in enzootic areas of the disease, as well as the life cycle and biology of trematodes and its effects on man should be elucidated.

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 1 880 Melanopsis praemorsa snails were collected from different fresh water bodies in Palestine from October, 2008 to November, 2010. Cercariae in Melanopsis praemorsa snails 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 microcercous cercaria, xiphidiocercaria and brevifurcate lophocercous cercaria. These cercariae called Cercaria melanopsi palestinia I, Cercaria melanopsi palestinia II and Cercaria 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 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 their development within the snail. Conclusions: These results have been recorded for the first time and these cercariae may be of medical and veterinary importance.

OBJECTIVETo detect the species of larval trematodes (cercariae) in Melanopsis praemorsa snails from 5 different fresh water bodies in Palestine.

METHODSA total of 1 880 Melanopsis praemorsa snails were collected from different fresh water bodies in Palestine from October, 2008 to November, 2010. Cercariae in Melanopsis praemorsa snails were obtained by lighting and crushing methods. The behavior of cercariae was observed using a dissecting microscope.

RESULTSThree 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 microcercous cercaria, xiphidiocercaria and brevifurcate lophocercous cercaria. These cercariae called Cercaria melanopsi palestinia I, Cercaria melanopsi palestinia II and Cercaria 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 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 their development within the snail.

CONCLUSIONSThese results have been recorded for the first time and these cercariae may be of medical and veterinary importance.

Animals ; Cercaria ; Fresh Water ; Host-Parasite Interactions ; Larva ; Snails ; parasitology ; Trematoda ; physiology