Study on 6-DMAP induced triploid of Crassostrea ariakensis from Huanghe River estuary

To obtain efficient induction method of Crassostrea ariakensis by 6-DMAP, we conducted triploid induction of C. ariakensis under the factors of induction concentration, initial induction time, and induction duration. Samples of C. ariakensis in age of 4—5 years were collected from Dongying City, Shandong, near the Huanghe (Yellow) River mouth. The cleavage rate, hatching rate, triploid rate, and condition of triploid larval population in different induction combinations were studied. Results show that the degree of influence of the three factors on triploid induction was in the order of initial induction time > induction duration > induction concentration. At 25°C, the best induction effect was obtained under the induction concentration of 300—450µmol/L, the induction of 14min after fertilization, and the duration of 15min. The induction rate of triploid was 51.39%—71.67%, the cleavage rate, hatching rate, shell height mean daily growth and mean survival rate of induced triploid larvae were 65.16%—81.57%, 61.25%—86.78%, 8.76—9.88µm/d, 69.16%—73.29%, respectively, and the triploid rate of eye-spot larvae reached 53.33%—62.16%. This study provides a theoretical basis for triploid induction of C. ariakensis in Huanghe (Yellow) River mouth region.