Optimal conditions for three brood chronic toxicity test method using a freshwater macroinvertebrate Moina macrocopa

Freshwater cladocera such as Daphnia magna and Ceriodaphnia dubia have been used extensively for freshwater toxicity test worldwide. However, these species may not be indigenous in certain geographical regions, which restrict the utility of these organisms as test species. In the present study, we investigated optimal culture and test conditions for an indigenous freshwater macroinvertebrate of Korea, Moina macrocopa. The culture conditions that were evaluated included water temperature (20°C and 25°C), rearing media (moderately hard water or MHW, with or without selenium supplementation, or Elendt M4), and food density (2.5 × 10(7) and 5 × 10(7) cells/mL of Selenastrum capricornutum), and their effects on the life history characteristics of M. macrocopa were determined. Population growth rate of M. macrocopa was maximized at 25°C with 5 × 10(7) cells/mL of algal food density in MHW. A series of chronic three brood reference toxicant tests were conducted under the ideal culture conditions that were identified here, and the results of the tests indicated reliable reproducibility of the test protocol. Optimal culture and test conditions that were identified for M. macrocopa in the present study are suggested for evaluation of chronic toxicity of chemicals and industrial or municipal discharge.