Distribution of Pulmonate Snail Indoplanorbis Exustus in Relation to Variant Abiotic Factors in and around Water Bodies of Doon Valley, Uttarakhand

The present communication deals with the distribution and population fluctuation of Indoplanorbis exustus under the impact of variant abiotic factors in Doon Valley, Uttarakhand. Further the study also revealed the effects of some physico-chemical parameters, like pH, water temperature, dissolved oxygen, free carbon dioxide on the occurrence and abundance of snail Indoplanorbis exustus in the vicinity of Doon Valley. The study involved sampling for a year from water bodies of various localities of Doon valley. Analysis of the data revealed that the physico-chemistry of the stream exercised profound effect on the distribution and population fluctuation of the fresh water snails. Significant changes in freshwater snail assemblages were primarily due to changes in the water quality from locality to locality. Coefficient of correlation (r) between population and physico-chemical parameters revealed significant relationship with population of the snail Indoplanorbis exustus. The study also revealed the existence of seasonal variation in the incidence of the species surveyed in different localities. The highest incidence of the snail have been found in monsoon season followed by post monsoon and winter seasons, while least incidence was reported in summer season indicated its thermophobic nature. The species was also found positive for different types of cercarial infection in selected localities.