Two fresh water bivalves viz. Lamellidens marginalis and Parreysia favidens were recorded from water reservoirs in and around Lucknow (U.P.) India. Shell microstructure of both the species indicate presence of periostracum, prismatic and nacreous layers. The shell of P. favidens appeared more thicker, particularly the nacreous layer. Behaviour of both bivalve species as well as their prospective role in pearl culture industry has been discussed.