Environmental conditions and culture method effects on growth and survival of juvenile winged pearl oyster, Pteria Penguin

Juvenile winged pearl oysters, Pteria penguin, were cultured for 6 mo in three commonly used culture units (panel nets, plastic mesh trays, and pyramidal pearl nets) at two dissimilar sites Pioneer Bay (a coral reef environment in which P. penguin are naturally present) and Cape Ferguson (a coastal semiestuarine area with high levels of silt deposition)- -to determine the effects of site and culture method on growth, survival, and fouling. Mean growth increases were recorded for the dorsoventral measurement (DVM), anteroposterior measurement (APM), shell thickness, and whole weight. At Pioneer Bay, five replicates for each of the three culture unit types were suspended at 3 m and at 6 m, and mean initial DVM was 28.0 [+ or -] 0.6 mm (n = 190). At Cape Ferguson, there were five replicates for each culture unit at 3 m only, and mean initial DVM was 28.0 [+ or -] 0.6 mm (n = 86). Mean growth increase at the end of the experiment for oysters at Pioneer Bay and Cape Ferguson, respectively, were 26.6 [+ or -] 1.0 mm and 32.6 [+ or -] 2.4 mm DVM. 29.6 [+ or -] 1.2 mm and 34.0 [+ or -] 2.9 mm APM. 6.7 [+ or -] 0.3 mm and 9.7 [+ or - ] 0.5 mm shell thickness, and 16.5 [+ or -] 0.7 g and 23.0 [+ or -] 2.1 g whole weight. For all growth parameters, mean increase was significantly higher under high- turbidity conditions at Cape Ferguson (P < 0.05). Culture unit also affected growth, with oysters held in mesh trays showing significantly more growth at both sites (P< 0.05). Mean survival of oysters at Cape Ferguson (96.5%) was significantly higher than at Pioneer Bay (79.4%). Depth had no significant effect on growth, survival, or fouling. The results indicate that site selection and culture unit are important parameters for optimizing growth and survival during nursery phase culture of P. penguin