Meeting Abstract

P1-86  Friday, Jan. 4 15:30 – 17:30  Effects of salinity on cellular energy budget of biomineralizing tissues of marine bivalves IVANINA, AV*; SOKOLOVA, IM; University of North Carolina at Charlotte, Charlotte, NC, USA ; Department of Marine Biology, University of Rostock, Rostock, Germany aivanina@uncc.edu

Shell 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, and this process is an energetically demanding. The aim of this study was to determine whether energy costs of biomineralization increase under the conditions unfavorable for CaCO₃ deposition and if so, which cellular functions might be responsible for that. Two species with different shell mineralogy (Crassostrea gigas and Mercenaria mercenaria) were exposed for 2 weeks to 3 salinities (30, 18 or 10) and cellular energy demand for protein synthesis, bicarbonate turnover, Ca²⁺ transport, and H⁺ transport was measured in ME cells and HCs. In clams’ ME, the energy demand was similar for the 4 studied cellular processes. Acclimation of clams to 10 PSU led to allocation of energy into the protein synthesis and bicarbonate production. The energy allocation of the oysters’ ME and HCs into the 4 studied cellular processes was balanced at salinity 30 PSU, whereas at 18 PSU an energy flux was diverted to the protein synthesis and H⁺ transport. Acclimation to 10 PSU led to major decrease of energy demand for all 4 cellular processes in oyster HCs. In the oysters’ ME energy allocation into the studied cellular processes at 10 PSU was similar to that at 30 PSU. Our data indicate that energy cost of biomineralization in M. mercenaria and C.gigas have different sensitivity to low salinity. In oysters, the energy costs of biomineralization-related functions of HCs and ME cells were highly affected by lowest salinity, where in clams the energy costs for biomineralization were robust to all tested experimental conditions.