The Inorganic Composition of Molluscan Extrapallial Fluid

Abstract

The inorganic composition of the extrapallial fluids of Mercenaria mercenaria, Mytilus edulis and Crassostrea virginica was significantly different from sea water. Calcium was the principal ion bound in the extrapallial fluids. This binding was accomplished by a non-dialyzable component that appeared to be a glycoprotein.

δ<sup>11</sup>B as monitor of calcification site pH in marine calcifying organisms

“…Corals are thought to accrete CaCO3 directly from a discrete calcifying fluid (e.g., Cohen and McConnaughey, 2003 and references therein;Al-Horani et al, 2003;Cohen and Holcomb, 2009;Gaetani and Cohen, 2006;Ries, 2011a), with mineralization sites and crystal orientations being influenced by organic templates and/or calicoblastic cells (e.g., Cuif and Dauphin, 2005;Goldberg, 2001;Meibom et al, 2008;Tambutté et al, 100 2007). Mollusks are also thought to precipitate their shells from a discrete calcifying fluid between the external epithelium of the mantle and the inner layer of the shell known as the extrapallial fluid (e.g., Crenshaw, 1972), with hemocytes and organic templates playing a potentially important role in crystal nucleation (e.g., Mairie et al, 2012;Mount et al, 2004;Weiner et al, 1984). Coralline red algae, such as those belonging to the family Corallinaceae, are also thought to precipitate high-Mg calcite (and/or aragonite) crystals from an intercellular calcifying fluid (Simkiss and Wilbur, 1989).…”

“…Mollusks, such as oysters, construct their shells of LMC (aragonite 405 during the larval stage) from a discrete calcifying fluid known as the extrapallial fluid ('EPF';e.g., Crenshaw, 1972), with hemocytes and organic templates playing a potentially important role in crystal nucleation (e.g., Wilbur and Saleuddin 1983;Wheeler 1992;Marie et al, 2012;Weiner et al, 1984;Mount et al, 2004).). The sample of C. virginica evaluated in this study was exposed to seawater conditions (pH = 8.2; 25 °C; 32 psu; (Crenshaw, 1972;Littlewood and Young, 1994;Michaelidis et al, 2005).…”

Ecomorphological Analyses of Marine Mollusks' Shell Thickness of <i>Rapana venosa</i> (VALENCIENNES, 1846) (Gastropoda: Muricidae)

“…This is achieved via membrane pumps and active transport across tissues. In molluscs the extrapallial fluid has a Ca 2+ concentration that is higher than seawater, usually by 15-25% (Crenshaw, 1972;Wilbur and Saleuddin, 1983;Furuhashi et al, 2009). This percentage is close to the maximum value obtained by us from the difference in salinity (13.75%) for R. venosa.…”

Barium uptake into the shells of the common mussel (Mytilus edulis) and the potential for estuarine paleo-chemistry reconstruction

“…The EPF is isolated from seawater and therefore may have different elemental concentrations than seawater. Although there are numerous reports on central EPF elemental concentrations (e.g., Crenshaw, 1972;Wada and Fujinuki, 1976), direct measurements of the marginal EPF are difficult and we know of only one report providing marginal EPF elemental concentrations, but 450 unfortunately Ba was not measured (Lorens, 1978). However, there does not seem to be a difference in Ba concentrations between hemolymph and central EPF in other bivalve species (A. Lorrain, unpublished data).…”