- Ocean acidification adversely affects the gonadal performance of mussels.
- Hypoxia does not have effects on fecundity of mussels.
- Steroids and Wnt/β-catenin gene expressions have weak correlations with fecundity in mussels.
Ocean acidification and hypoxia have become increasingly severe in coastal areas, and their co-occurrence poses emerging threats to coastal ecosystems. Here, we investigated the combined effects of ocean acidification and hypoxia on the reproductive capacity of the thick-shelled mussel Mytilus coruscus. Our results demonstrated low pH but not low oxygen induced decreased gonadosomatic index (GSI) in mussels. Male mussels had a lower level of sex steroids (estradiol, testosterone, and progesterone) when kept at low pH. Expression of genes related to reproduction were also impacted by low pH with a downregulation of genes involved in gonad development in males (β-catenin and Wnt-7b involved in males) and an upregulation of testosterone synthesis inhibition-related gene (Wnt-4) in females. Overall, our results suggest that ocean acidification has an impact on the gonadal development through an alternation of gene expression and level of steroids while hypoxia had no significant effect.
Wang T., Kong H., Shang Y., Dupont S., Peng J., Wang X., Deng Y., Peng J., Hu M. & Wang Y., in press. Ocean acidification but not hypoxia alters the gonad performance in the thick shell mussel Mytilus coruscus. Marine Pollution Bulletin 167. Article (subscription required).