Model construction and optimization of larval growth and survival in the pearl oyster, Pinctada fucata

Abstract

This study investigated the changes in growth and survival of pearl oyster P. fucata larvae under simultaneous variations in temperature and salinity for the first time. Results showed that larval growth and survival increased with the simultaneous variation of temperature and salinity up to a peak, beyond which they began to decline. Significant temperature-salinity interactions were found synergistic (positive) for larval growth and survival. Both temperature and salinity exerted significant impacts on larval growth and survival, but temperature was the dominant factor. Polynomial models of larval growth and survival were established, with adjusted and predictive coefficients of determination more than 96 % and 89 %, respectively. Lack-of-fit tests and residuals analyses showed high adequacy of these models. The best larval growth was basically achieved at the same temperature-salinity conditions as those of the best larval survival. Through simultaneously maximizing the models established, larval growth and survival were found optimal at temperature/salinity conditions of 28 °C/30, with desirability as high as 98.1 %. The models developed in this study could be applied to reliably monitoring and predicting larval growth and survival under simultaneous variations in temperature and salinity, contributing to more efficient larviculture of the pearl oyster species.