Studies on Hydrobiology in relation to Occurrence and distribution of Molluscs in Fish ponds at National Fish Seed Farm, Karnataka
H.M. Ashashree1 and B.R. Kiran2
1Assistant Professor, Department of Zoology, Sahyadri Science College, Shivamogga - 577 203 (India) 2Research & Teaching Assistant in Environmental Science, DDE, Kuvempu University, Shankaraghatta - 577451 (India)
ABSTRACT
This article deals with the distribution and variety of aquatic molluscs in relation to physico-chemical parameters of maure fed fish rearing ponds of National fish farm of Karnataka, India for the duration of April to September 2021. A total of 17 species and 14 genera belonging to 8 families of molluscans were identified. Numerical abundance of total population registered 2100±75/m2 to 4500±155/m2. The genus composition of molluscans during this period comprised of Filopaludina (40%), Indo planorbis (5%), Lymnaea (12%), Campeloma sp. (5%), Lamellidens (1%), Viviparus (5%), Radix sp. (5%), Melanoides sp (5%), Thiara (2%), Bellamya (12%), Margaritifera (1%), Idiopoma sp (2%) and Gyraulus sp (5%) respectively . Gastropda constitute 83.33% and Bivalve contribute 16.67% respectively Filopaludina species showed dominant followed by Bellamya and Lymnaea with 12%. Total aquatic molluscans showed seasonal variation being peak density in summer while, minimum in winter. Among families, Lymnaeidae consists of 5 species followed by Viviparidae with 4 species. Planorbidae, Thiaridae and Unionidae consists of 2 species each and rest of the families having 01 species each respectively. Regarding water quality, water temperature, phosphate and dissolved organic matter have significant effect on species composition and seasonal abundance.