Environ Toxicol Chem. 2021 Dec 16. doi: 10.1002/etc.5273. Online ahead of print.
ABSTRACT
The post-ecdysial mineralization in crustaceans involves the deposition of carbonate salts, such as calcium carbonate, to the organic matrix. Due to the resemblance between Pb2+ and Ca2+ , this study was carried out to investigate whether Pb is incorporated into the new shell during post-ecdysial mineralization using the blue crab, Callinectes sapidus, as the model crustacean. It was hypothesized that injected Pb would be deposited in the shell via calcium transporters in the epidermis during the mineralization process. Post-ecdysial blue crabs were injected with two doses of 5 µg Pb/g wet weight each in lead acetate and then Pb, Ca and Mg content were analyzed in the exoskeleton, while only Pb bioaccumulation was quantified for the hepatopancreas, gills, muscles, and hemolymph. Results showed a statistically non-significant increase in exoskeletal Pb content in Pb-treated crabs compared to control, suggesting that exoskeletal Pb may not be a sensitive proxy for aquatic Pb pollution. There was a significant decrease in Ca content in Pb-treated crabs, suggesting that Pb hindered the deposition of Ca to crab exoskeleton, thereby obstructing calcification. A trend of decrease in exoskeletal Mg was also observed in Pb-treated crabs. There was a significant increase in Pb content found in the gills, hepatopancreas, muscle, and hemolymph in Pb-treated crabs. The rank of the Pb level amongst three soft tissues in a decreasing order is: hepatopancreas > gill > muscle. This study is the first to present evidence that Pb disrupts post-ecdysial exoskeletal calcification in a crustacean. This article is protected by copyright. All rights reserved.
PMID:34913519 | DOI:10.1002/etc.5273
