Kapis, popularly known as the “window-pane shell” or pearl oyster, is commercially propagated in the mud-choked tidal flats of Bacoor Bay at sitios Binakayan, Kawit, and Panamitan, Noveleta, Cavite Province. The practice has been carried on for a number of years as part time industry for the principal pur¬pose of raising good quality shells for the window sash facto¬ries, and novelty shops in Manila and its environs. The meat content of the kapis, considered only as a by-product of the industry is used for table preparations or dishes such as guinamos, adobo, chowder, and omelet.
Window pane shells are sedentary bivalves, favorably raised in shallow estuarine lagoons, coves and small bays with water salinity ranging from 10 to 35 per mille and with a bottom of blue mud sediments.