Effects of different densities of Isochrysis aff. galbana and Chaetoceros calcitrans on some growth parameters and survival rate of winged pearl oyster spat, Pteria penguin

The growth performance and survival rate of spats of winged pearl oyster (Pteria penguin) fed with two microalgae, Isochrysis aff. galbana and Chaetoceros calcitrans, as well as the combination of both species over a period of 60 days, was evaluated. The microalgal density was considered 50000 cell.ml-1 in all treatments. The spats divided into 5 different groups; (1) spats fed exclusively with I. aff. galbana; (2) those fed with the ratio of 70:30 I. aff. galbana and C. calcitrans; (3) spats fed with 50:50 I. aff. galbana and C. calcitrans; (4) those fed with 30:70 I. aff. galbana and C. calcitrans; and (5) individuals fed exclusively with C. calcitrans. Results demonstrated that total length was significantly higher in treatments 2, 3, and 4 in compare to 1 and 5. However, heel length was same for all treatments. The thickness of treatment 2 was significantly higher than both treatments 1 and 5. This value was not different between treatments 3 and 4 with 1, but significantly higher than that of treatment 5. Survival rate was same for all treatments. According to the obtained results, feeding with a combination of both microalgae is recommended for the culture of P. penguin spat.