THE EFFECT OF SPAT DENSITIES ON THE ATTACHMENT EFFICIENCY OF PORTUGUESE OYSTERS LARVAE (Crassostrea angulata)

Abstract

This study was carried out to evaluate the effect of spat densities on the attachment efficiency of Portuguese oysters larvae (Crassostrea angulata). The experiment was assessed at densities of 60 larvae/L, 80 larvae/L, and 100 larvae/L in 500L plastic tanks. Each treatment of rearing densities was evaluated in 02 methods of attachments. Each treatment was run in triplicate. The results showed that the attached rate of spat was the highest in 80 larvae/L (68.76%), followed by the density of 100 larvae/L (50.63%), and the lowest is 100 larvael/L (33.56%). Meanwhile, the survival rate of bottom attachment was similar to that of suspended attachment and there was not statistically significant between both methods (P>0.05). From the above results, Portuguese oysters spat should be reared at a density of 80 larvae/L to reach the highest rearing efficiency.