Background Oysters possess formidable metal accumulation capabilities, earning them the title of hyperaccumulators of copper and zinc. Furthermore, they can survive normally even after accumulating significant amounts of these metals, demonstrating exceptional metal tolerance. Individual differences in oyster metal accumulation abilities are notably significant, representing a quantitative trait. Studies including enrichment kinetics and whole-genome association analyses have elucidated mechanisms underlying differences in oyster metal accumulation capabilities. However, whether these differences in accumulation capabilities affect metal tolerance remains inconclusive.

Objective Investigating the differences in copper and zinc tolerance among oysters with varying metal accumulation capacities at different developmental stages.

Methods This study utilized high copper-zinc accumulating strains and low copper-zinc accumulating strains of Fujian oysters (Crassostrea angulata) to conduct experiments. Metal contents in parental C. angulata of different strains were measured, and acute toxicity tests for copper and zinc were performed on D-shaped larvae and 6-month-old adults of both strains, calculating the median lethal concentration (LC₅₀).

Results There were significant differences in copper and zinc contents between parental C. angulata of the two strains. During the D-shaped larval stage, the 24-hour zinc LC₅₀ of larvae from the low accumulation strain was significantly lower than that of larvae from the high accumulation strain, while the 24-hour copper LC₅₀ showed no significant difference between the two strains. Thus, the high accumulation strain exhibited significantly greater tolerance to zinc than the low accumulation strain, but both strains showed no significant difference in copper tolerance. In the adult stage, the copper and zinc LC₅₀ values at 96 hours for adults of the high accumulation strain were higher than those of the low accumulation strain, indicating significantly greater tolerance to copper and zinc in the high accumulation strain compared to the low accumulation strain.

Conclusion This study lays the groundwork for exploring the relationship between oyster metal accumulation capability and its tolerance, further providing insights into oyster metal accumulation and detoxification mechanisms. Additionally, research on oyster metal accumulation and tolerance phenomena is crucial for ensuring food safety and utilizing oysters as indicators for environmental monitoring.