Effects of food and water quality on culturing ofCeriodaphnia dubia

Abstract

AbstractThe U.S. Environmental Protection Agency (EPA) has developed a 7‐d test to evaluate effluent effects onCeriodaphnia dubiasurvival and reproduction. Several foods have been used to culture and testCeriodaphnia dubiain both laboratory waters and surface waters with variable results. This study's objective was to evaluate effects of eight diets on survival and reproduction ofCeriodaphnia dubiain hard reconstituted water (HRW); HRW was used alone or supplemented with bacteria or selenium to determine whether their addition would improve survival and reproduction. Diets consisted of yeast, trout food (TF), yeast/trout food/Cerophylc̊ (YTC),Selenastrum capricornutum, Ankistrodesmus convolutus, Chlamydomonas reinhardii, Selenastrum capricornutumplus TF, andSelenastrum capricornutumplus YTC. Screening tests in HRW with each diet (at several levels) were first used to rank diets; diets with high survival (®80% at 14 d) and reproduction (®3 young per female per reproductive day) were further evaluated in multigeneration feeding tests. Finally, diets yielding high survival and reproduction in HRW were evaluated in surface and well water to verify adequacy in waters of differing composition and quality. Yeast, trout food, YTC,Selenastrum capricornutum, Ankistrodesmus convolutus, orChlamydomonas reinhardiiused alone were unacceptable for long‐term culturing in HRW under test conditions used in this project. Success of the EPA's recommended food, YTC, was dependent on water, with worst results in HRW. The addition of selenium and bacteria to the HRW did not consistently improve either survival or reproduction ofCeriodaphnia dubiain the diet tests. Some of the diet test results were confounded by the use of batches of HRW that periodically contained some unidentified components that were toxic toCeriodaphnia dubia. BothSelenastrum capricornutumplus TF andSelenastrum capricornutumplus YTC were acceptable for culturing with high survival and reproduction.