Figure 1.
Mean (± S.D of 5 replicate cultures) pH (NBS scale) change during the pre-settlement and post-settlement (juvenile) oyster growth experiment.
Table 1.
Representative values of carbonate system parameters in the three pH treatment culture containers during larval (pre-settlement) and juvenile (post-settlement) growth period.
Figure 2.
Effects of pH on different developmental stages of the Pacific oyster (Crassostrea gigas) on day 11 (A) and day 16 (B) post-fertilization.
Each data point represents the mean ± SD of five replicate cultures. For each replicate measurement, 20 to 200 larval samples were used.
Figure 3.
Cumulative percent-frequency distribution of the Pacific oyster (Crassostrea gigas) larval shell size at three pH levels (pH 8.1, 7.7 and 7.4) on day 11 (A) and day 16 (B) post-fertilization.
Figure 4.
Respiration or oxygen consumption (A), feeding or filtration (B), and organic tissue weight or ash-free dry weight (C) of the pediveliger larvae of the Pacific oyster (Crassostrea gigas) cultured at three pH levels (pH 8.1, 7.7 and 7.4).
Pediveliger larvae with similar shell size (∼280 µm in length) and age (16 day post-fertilization) from all three pH levels were used simultaneously for each measurement. Each data point represents the mean ± SD of five replicate cultures except respiration, where there were only three randomly selected replicates. For each replicate measurement, 200 larval samples were used. Statistically different mean values (Tukey’s multiple comparison test results) are indicated with different letters.
Figure 5.
Effects of pH on the post-settlement (early juvenile) shell growth rate of the Pacific oyster (Crassostrea gigas).
The growth rates for each pH were calculated from days 5 to 12 post-settlement. Each data point represents the mean ± SD of three replicate cultures. For each replicate measurement, one to 20 juvenile samples were used. The statistically different mean values (Tukey’s multiple comparison test results) are indicated with different letters.
Figure 6.
Cumulative percent-frequency distribution of the Pacific oyster (Crassostrea gigas) juvenile shell growth rates at three pH levels (pH 8.1, 7.7 and 7.4) on day 5 (A) and day 12 (B) post-settlement.
Figure 7.
SEM images showing the ultrastructure of the early juvenile shells (42 day post-settlement) of the Pacific oyster (Crassostrea gigas) cultured at three pH levels (pH 8.1, 7.7 and 7.4).