Standardized methods for acute and semi-chronic toxicity tests with the copepod Acartia tonsa

The availability of standardized protocols both for organism culture and bioassay with ecologically relevant species is of great concern in ecotoxicology. Acartia tonsa represents an important, often dominant, member of zooplankton communities and meets all the practical criteria suggested for model species. New standardized procedures for laboratory culturing of the copepod A. tonsa and standardized methods for acute (24 and 48-h) and semi-chronic (7-d, static-renewal) toxicity tests with the nauplius stage are described. In both cases, eggs are the starting stage and nauplius immobilization is the endpoint. The methods were the object of an inter-comparison test involving 9 laboratories; nickel was the reference toxicant. Relative reproducibility was 24, 25, and 34% for 24-h, 48-h, and 7-d tests, respectively.