Status of Temporary Wetland of Paddy Field Associated Molluscs of Coastal Karnataka: A Case study

Freshwater molluscs contribute to the ecosystem by increasing soil fertility and nutrient cycling.The study was designed to estimate the diversity and abundance of molluscs from the coastal paddy fields of Karnataka state of India.Six paddy fields of Karnataka state were selected for the study from June-November 2017 and 2018 whereas the paddy field of Marlimar was surveyed from June 2017-April 2018, June 2018-March 2019 as the paddy cultivation occurs up to two cropping cycles.Presence of Idiopoma dissimilis, Indoplanorbis exustus, Physella acuta, Pila virens Racesina luteola P. virens I. exustus and was observed from paddy fields.and were in most of the paddy fields of coastal Karnataka.Abundance of snails increased in the initial months of cropping and declined towards the harvest of the paddy.Snail diversity was highest in the paddy field of Marlimar and least in Mattu.pH of water ranged between 3.54 and 8.53, Electrical conductivity 3.89-1136μS/m, soil pH 3.07-7.08,and soil organic carbon 0.06-3.51%.Significant difference in salinity, the electrical conductivity of water and soil organic carbon was observed between the paddy fields.Precipitation, pH of soil and water correlated significantly with diversity of snails.Paddy fields, due to their unique ecological conditions and water holding capacity are suitable habitats for the snails.They are heterogeneous habitats providing space, shelter, and food for the survival of snails.Sustainable management of paddy fields is required to conserve the snail species associated with them.