The culture of pearl oysters, Pinctada fucata (Gould, 1850) in Phuket with temperature shock method and survival rates on various feeds

Marine pearl farming at Phuket Island has exploited natural pearl oysters. In order to obtain sufficient pearl oysters, Pinctada fucata (Gould, 1850), the oyster cultivation was carried out to determine appropriate kinds of food and types of spat collectors. The male and female oysters were stimulated to spawn with this temperature shock method (treated with 32oC and then with 26oC). The fertilized eggs developed into the stages of polar body, cleavage, blastula, gastrula, trochophore and then D-shape larvae. At the ageof 19-26 hrs. the larvae were fed with three kinds of food: Isochrysis galbana, Chaetoceros calcitrans and the mixture of 1:1 I. galbana and C. calcitrans. Upon the first 30 days, shell lengths of the spats fed with I. Galbana, C. calcitrans and the mixture were 422.00±59.32, 221.33±12.46 and 347.33±67.98 μg, respectively. The 26-29th day spat stage settled to the collectors: saran net, plastic plates and wavy tile. Number of spats settling to saran net was the highest. But after being moved into the sea for 30 days, the survival rate was89.06% which was lower than for those settling to plastic plates (93.29%) and wavy tile (93.99%).