How Does Carbon Dioxide–Induced Acidification Affect Postecdysial Exoskeletal Mineralization in the Blue Crab ( Callinectes sapidus )?

• Published in: Environmental Toxicology and Chemistry
• Main Authors: Soorya, Yusra, Zou, Enmin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2022
• Subjects: Health, Toxicology and Mutagenesis; Environmental Chemistry; Ocean acidification
• Online Access: http://dx.doi.org/10.1002/etc.5474; https://onlinelibrary.wiley.com/doi/pdf/10.1002/etc.5474; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/etc.5474; https://setac.onlinelibrary.wiley.com/doi/pdf/10.1002/etc.5474

Abstract Carbon dioxide (CO 2 ) enrichment in seawater because of increased use of fossil fuels can possibly cause detrimental effects on the physiological processes of marine life, especially shell builders, due to CO 2 ‐induced ocean acidification. We investigated, for the first time, specifically the effect of CO 2 enrichment on postecdysial shell mineralization in Crustacea using the blue crab, Callinectes sapidus , as the model crustacean. It was hypothesized that CO 2 enrichment of seawater would adversely affect exoskeletal mineralization in the blue crab. We used two groups of postecdysial crabs, with one group exposed to seawater at a pH of 8.20 and the other group treated with CO 2 ‐acidified seawater with a pH of 7.80–7.90. After a period of 7 days, samples of exoskeleton and hemolymph were collected from the survivors. Enrichment was found to significantly increase exoskeletal magnesium content by 104% relative to control, whereas a statistically nonsignificant elevation of 31% in exoskeletal calcium was registered. Because CO 2 treatment did not change the content of magnesium and calcium in the hemolymph, we postulate that increased exoskeletal mineralization in postecdysial blue crabs must stem from an increased influx of bicarbonate ions from the medium through the gill, to the hemolymph, and across the epidermis. In addition, the observed significant increase in the mass of exoskeleton following CO 2 treatment must be at least partly accounted for by enhanced postmolt carbonate salt deposition to the shell. Environ Toxicol Chem 2022;41:2950–2954. © 2022 SETAC