Dilution of Seawater Affects the Ca2 + Transport in the Outer Mantle Epithelium of Crassostrea gigas
J. Kirsikka Sillanpää, João C. R. Cardoso, Rute C. Félix, Liliana Anjos, Deborah M. Power, Kristina Sundell
Abstract
Varying salinities of coastal waters are likely to affect the physiology and ion transport capabilities of calcifying marine organisms such as bivalves. To investigate the physiological effect of decreased environmental salinity in bivalves, adult oysters (Crassostrea gigas) were exposed for 14 days to 50% seawater ( Exposure of oysters to a salinity of 14 decreased the active mantle transepithelial ion transport and specifically affected Ca 2+ transfer. Gene expression of the Na + /K + -ATPase and the sarco(endo)plasmic reticulum Ca 2+ -ATPase was decreased whereas the expression of the T-type voltage-gated Ca channel and the Na + /Ca 2+ -exchanger increased compared to animals maintained in full SW. The results indicate that decreased environmental salinities will most likely affect not only osmoregulation but also bivalve biomineralization and shell formation.