Translator Disclaimer
17 April 2019 In situ Measurements of pH, CA2+, and Dic Dynamics within the Extrapallial Fluid of the Ocean Quahog Arctica islandica
Author Affiliations +
Abstract

This study investigated to what extent the extrapallial fluid (EPF) of the marine bivalve Arctica islandica (Linneaus, 1767) is involved in shell formation. With in situ pH microscopy, pH gradients were identified between inner shell surface and outer mantle epithelium (OME). pH at the OMEvaried rapidly between neutral and values above 9, suggesting active H+ pumping. Microsensor measurements showed also remarkable short-term dynamics in pH and Ca2+ concentrations, again suggesting active ion pumping. Further focus was on pH, Ca2+, and dissolved inorganic carbon dynamics within the EPF to determine whether calcium carbonate precipitation is possible within the EPF. The data show that the bulk of the inner EPF rarely reaches calcium carbonate saturation and, thus, cannot be the site of shell formation. At the OME surface, however, pH levels of up to 9.5 were observed, corresponding to a 30-fold carbonate supersaturation. Thus, ion pumping by the OME can drive calcification when the OME is just a few mm distant from the inner shell surface, as it is the case in the outer EPF.

Kristina Stemmer, Thomas Brey, Martin S. Gutbrod, Martin Beutler, Burgel Schalkhausser, and Dirk de Beer "In situ Measurements of pH, CA2+, and Dic Dynamics within the Extrapallial Fluid of the Ocean Quahog Arctica islandica," Journal of Shellfish Research 38(1), 71-78, (17 April 2019). https://doi.org/10.2983/035.038.0107
Published: 17 April 2019
JOURNAL ARTICLE
8 PAGES


SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top