The triploid oysters also maintained higher dry meat weight and higher condition index (CI) values than their diploid siblings at all sites during the final 10 months’ growth to market size (40 to 60 g whole weight).
The
triploid oysters at the subtidal site had the highest CI values recorded in this study. When exposed to
the protistan parasite Mikrocytos roughleyi which causes winter mortality disease, no differences in
mortality between diploid and triploid groups occurred. These findings have major implications for
the N.S.W. oyster industry as triploid Sydney rock oysters can reach market size 6-18 months faster
and maintain better meat condition than diploid oysters without an increased risk of winter mortality.