The influence of cooling rate, developmental stage, and the addition of sugar on the cryopreservation of larvae of the pearl oyster Pinctada fucata martensii.

This paper examines the effects of cooling rate, developmental stage, and the addition of sugar on the cryopreservation of the larvae of the pearl oyster, Pinctada fucata martensii. The survival rates of frozen-thawed trochophores was 43.1% at a cooling rate of 1.0 degrees C/min. The survival rate of frozen-thawed larvae increased with developmental stage, except for umbo stage larvae, and the late D-shaped larvae showed a survival rate as high as 91%. The addition of sugar (0.2M glucose or sucrose) improved the survival rate of larvae. These results indicate that the preferred cooling rate, developmental stage, and sugar for the cryopreservation of pearl oyster larvae are 1 degrees C/min, late D-shaped larvae and 0.2M glucose or sucrose.