Variant abiotic factors and the infection of Fasciola gigantica larval stages in vector snail Indoplanorbis exustus

The aquatic environment has numerous physical and chemical parameters that may influence the physiology and maturation rate of parasite found inside the vector snail. It may be possible that abiotic factors (temperature, pH, CO2, O2 and conductivity) and higher population density of snails could promote the transmission of parasite and raise their local abundance. In the present paper, we examined that how these environmental factors affect the transmission of cercaria throughout the year 2009-2010. The infection of Fasciola gigantica larvae in Indoplanorbis exustus in Ramgarh Lake and GIDA pond was maximum in month of October (40%) and minimum in month of November (8.33%). Trend of higher infection in I. exustus was observed in July to October. This study conclusively, shows that variant abiotic factors in different months of the year can significantly alter the infection rate and development process of larvae (sporocyst, redia and cercariae) in the snail Indoplanorbis exustus. The paper also includes a discussion on the important factors that influence the timing of molluscicide operation for the control of fascioliosis in the Gorakhpur.