Cultivation of Oyster Crassostrea gryphoides (Schlotheim) through rafts at Ambra creek coastal belt of Arabian sea, Sindh Pakistan

Abstract

Cultivation of edible oyster Crassostrea gryphoides on rafts was carried out for the first time in Pakistan during 2009 to 2011. 10 pilot rafts were fixed at Ambra creek an estuarine area of Indus river delta eco-region. Appearance of 8 to 12 tiny spats size average 0.4cm ± 0.158 diameter were evident on submerged old empty shells of oyster in June 2010. The development of crop was studied bi-monthly for size length measurement 2.82±0.526, 4.66±0.364, 6.18±0.465, 7.6±0.291, 9±0.689 and 12.3±0.51cm respectively in period of 13 months. Ideal increment in growth of animal was observed in summer season and leisurely growth in length and width of oyster was recorded during winter months. Physico-chemical parameters vs. temperature of air and water, transparency, pH, alkalinity, hardness, salinity, conductivity, total dissolved solids, dissolved oxygen and depth variation in water of the creek were analyzed and found suitable for oyster farming. Secchi disc reading indicated that water was light green which is a clear indication of phytoplankton productivity. The habitat is rich with natural food items for oyster spats, larvae and juvenile. The growth performance of the oyster was remained quite satisfactory in the ecology of Ambra creek.