Silver deprivation limits fecundity and survivability in the freshwater crustacean, Daphnia magna.

The nutritional role of silver for the freshwater crustacean, Daphnia magna, was examined through four generations of deprivation. Silver inclusion in animal media was set at a nominal zero (employing chemicals of the highest available purity). Both reproduction (-60%) and life span (-40%) were negatively affected when compared to animals reared in the presence of 0.4 ng g(-1) Ag. These results strongly suggest a nutritional requirement of silver for daphnids at nanomolar concentrations.