Abstract: This study examined the impacts of ocean acidification projected to occur by the year 2100 on the development of Pinctada martensii embryo and early larva. Artificially fertilized eggs were cultured in the seawater with pH 7.70 (acidified by CO₂, acidified group) and pH 8.10 (control group). After treated for 8 h, no obvious difference was observed in the quantitative distribution of embryo in its different development stages between acidified group and control group. After 24 h, 16.6%±12.0% of the embryo in acidified group developed into D-shaped veliger larvae, and the percentage of teratogenic larvae was 48.2%±9.1%, as compared 44.8%±7.4% and 18.6%±11.5% in control group, respectively. After 48 h, 23.0%±9.6% of the embryo in acidified group developed into D-shaped veliger larvae, and the percentage of teratogenic larvae was 63.2%±14.1%, while the corresponding values in control group were 59.4%±13.0% and 26.6%±14.5%, respectively. Comparing with those in control group, the shell length and height of D-larvae in acidified group were obviously lesser, and the development of the larvae was much slower. This study indicated that ocean acidification in the future would give negative effects on the larval development of  calcifying marine organisms, such as P. martensii.

Key words: Soil microorganism, Extraction and purification