On predicting the setting season of the oyster Crassostrea iredalei in Himamaylan River, Negros Occidental

Abstract

A spatfall forecasting program in April-November 1981 suggests that daily counts of larvae in plankton samples may be used to forecast spatfall of C. iredalei . Counts of at least five ready-to-settle larvae per 100-liter sample for three to five days indicate that spatfall will occur very soon and that collector materials should be put out immediately.

Oyster spatfall was good in the months of July, August, and September. Highest larval count was 247 ready-to-settle larvae per 100-liter plankton sample; this led to a record set of 2,423 oyster spat on a string of thirteen shell cultch between August 24 and 31.