Ecology of oyster beds

The oysters of the world are grouped into one family Ostreidae. Within this family are 3 groups or genera viz., Ostrea, Crassostrea and Pycnodonta. This genus Ostrea which is widespread through most part of the world is generally considered to be adapted to clear waters with little sediment and high salinity. Crassostrea exist in estuaries wliere the silt load is high and salinity variable and generally low. Pycnodonta is a tropical open sea form and thrives in high salinity