Salinity-dependent sieve pore variability in Cyprideis torosa: an experiment

Abstract. Salinity-dependent sieve pore variability in Cyprideis torosa (Jones) is tested and confirmed through a culture experiment investigating valves from a salinity range between 0.6 and 14.8. In contrast to results from a previous study, the proportion of sieve pore shapes shows a slight offset at higher values probably caused by relatively lower calcium concentrations in our microcosms. Besides ion concentration, salinity variability and ion composition are assumed to be driving factors for sieve pore shapes, as for the case of noding in Cyprideis torosa. Despite some limitations in using sieve pore shapes as a proxy in quantitative salinity reconstructions in athalassic water bodies, an application for detecting trends and salinity changes in fossil associations and for quantitative reconstructions in marginal marine waters is feasible and adds a valuable salinity proxy, especially for the oligohaline to mesohaline salinity range.