COMBINED EFFECTS OF TEMPERATURE AND ALGAL CONCENTRATION ON SURVIVAL, GROWTH AND FEEDING PHYSIOLOGY OF PINCTADA MAXIMA (JAMESON) SPAT

D. Mills-2000

Journal of Shellfish Research, 19 (1) : 159-166 (from Current Contents)

Abstract :

To determine a suitable culture environment to maximize growth and survival, Pinctada maxima spat were held at 36 combinations of temperature and algal concentration for 14 days within a flowthrough system. Survival was greatest between 23 °C and 32 °C, with 35 °C resulting in high mortalities. The optimum temperature range for P. maxima spat found in this study agrees well with the observed temperatures which limit the natural distribution of P. maxima in Australian waters. Survival of spat was highest at low algal concentrations. Growth was optimal between 26 °C and 29 °C and at 54 algal cells/µl; however, growth was still acceptable at algal concentrations as low as 12 cells/µl. The organic content increased with feeding rate and was positively correlated with specific growth rate. Spat filtration rate declined at high feeding rates, whereas grazing rate increased, with a commensurate decline in conversion efficiency. It is recommended that P. maxima spat be maintained within the temperature range of 26 °C to 29 °C and at algal cell densities between 12 and 54 cells/µl to maximize spat performance and minimize algal wastage.

(Paspaley Pearling Co PL, POB 338, Darwin, NT 0801, Australia)

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