Effect of stocking density on growth and survival of the rainbow pearl oyster Pteria sterna (Gould 1852) during nursery and late culture in Bahia de La Paz, Baja California Sur, Mexico.

摘要

Growth and survival of the rainbow pearl oyster, Pteria sterna (Gould 1852), was evaluated in field culture at Bahia de La Paz, Mexico. Mexican made NestierTM trays were used in nursery culture from March to July 1999 at four different stocking densities (25, 50, 75 and 100 individuals/tray). Late culture proceeded from July 1999 to March 2000 in sandwich nets and rail cages. Each artifact received 70 to 75 individuals. We studied the long-term effect of nursery culture stocking treatments. Growth patterns were examined using shell volume (height x width x depth, in cm3). Survival was estimated monthly. Growth and survival were acceptable regarding routine operations, but variations in this experiment depended on stocking density and type of late culture device. The interaction of density and culture device was significant for shell volume at the end of the experiment (F=3614.14; p<0.0001). Final shell volume depended on stocking density in nursery culture (F=8.09, p<0.001), but culture device had no influence (F=0.76; p=0.3). The results indicated that growth and survival in nursery culture were not proportionally related with stocking density. The change to late culture improved overall response. Advantages in growth were favorable for D50 C only. Rail cages promoted better survival than sandwich nets. Based on the natural behaviour of P. sterna, the Optimal Stocking Density may be higher than the ranges tested in the present study. We recommend new strategies to improve the actual culture technology for P. sterna. A 3-dimensional culture unit might be an important advantage for this species regarding territorial exploitation and efficiency of spatial management in the production cycle..