Kannika Kanjanachatree, Kanoktorn Piyathamrongrut, and Wajjana Rativat

pp. 1 - 16

Abstract

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 age
of 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 26-29^th 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 was
89.06% which was lower than for those settling to plastic plates (93.29%) and wavy tile (93.99%).