Meeting Abstract

P3-109  Sunday, Jan. 6 15:30 – 17:30  Effects of salinity on activity of key biomineralization and acid-base regulation enzymes of Mercenaria mercenaria RIMKEVICIUS, T*; JARRETT, A; IVANINA, AV; SOKOLOVA, IM; University of North Carolina at Charlotte, Charlotte, NC, USA; Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburg, PA, USA; University of North Carolina at Charlotte, Charlotte, NC, USA ; Department of Marine Biology, University of Rostock, Rostock, Germany aivanina@uncc.edu

The molluscan exoskeleton provides mechanical support and protection from predators and environmental stressors. The mantle edge (ME) and hemocytes (HCs) play a major role in molluscan shell formation. Salinity is one of the key stressors that affect bivalve populations and is predicted to be decreased in the future. The aim of this study was to determine how conditions unfavorable for CaCO₃ deposition would affect cell-mediated shell biomineralization process in bivalves. Adult hard shell clam Mercenaria mercenaria were exposed for two weeks to three salinities (30, 18 or 10) and activity of biomienralization and acid-base regulation enzymes (Na/K ATPase, H⁺ ATPase, Ca²⁺ ATPase, carbonic anhydrase and chitin synthase) was measured in isolated ME cells and HCs. Salinity shifts has different effects on biomineralization enzymes from ME and HCs in clams. Activities of the studied biomineralization and acid base regulated enzymes from HCs was not affected by change in salinity, where Na/K ATPAse and Ca²⁺ ATPase activity in ME were elevated at intermittent salinity (18) compared to high (30) or low (10) salinity. Change in salinity regime had no effect of activity of carbonic anhydrase and chitin synthases in HCs or ME cells of clams.