Incidence of developmental stages (cercariae) of trematodes in aquatic snails

A total of 432 aquatic snails, collected from different water bodies (Villianur, Ossudu lake and Murungapakkam, Puducherry) were screened for cercariae. Following photostimulation method and crushing methods, three different types of cercariae, viz., xiphidiocercariae, amphistomecercariae and furcocercouscercariae were identified in which xiphidiocercariae (25.08%) was highest followed by amphistome cercariae (17.31%) and furcocercous cercariae (3.5%). One cercariae remained unidentified. Statistical analysis (Chi-square test) indicated that there was significant (p<0.01) association between type of snails and presence of xiphidio cercariae and amphistome cercariae. However, the relationship of snail and furcocercous cercariae was not significant (p>0.01). Highest cercarial infection of snails was observed in the month of March (60%) and lowest was in the month of June (10.34%). Overall incidence of cercariae was highest in Villianur (63.06%) followed by Murungapakkam (48.88%) and Ossudu Lake (28.25%). Chisquare test revealed there was a significant (p<0.001) association between the places (Villianur, Ossudu lake and Murungapakkam) and presence of xiphidio cercaria and amphistome cercariae in aquatic snails. A total of 100 gastrointestinal tracts of goats (82 non descript and 18 Jamnapari) collected from Manucipal Slaughter House and local meat retailer shops, Puducherry were examined during the above specified time. It was observed that these goats were also found highly infected with trematodes, cestodes and nematodes. The co-incidence of cercariae in snails and existence of trematodes in GI tract of goats alarmed about cercarial trematode infection to susceptible goats those grazing nearby water bodies in Puducherry.