Advanced tracking system of multiple Artemia and various behavioral endpoints for ecotoxicological analysis

Abstract

Abstract The movement of brine shrimp (Artemia spp.) was tracked to evaluate the complex interactions upon toxicant intake using a toxicological bioassay. In this study, we present a new method to assess the toxicity of environmental contaminants to Artemia and validate it using mercury as the toxicant model. We developed a multi-object tracking method that can simultaneously quantify the changes in behavioral characteristics of individual Artemia exposed to mercury ions (Hg2+). As the concentration of Hg2+ increased from 200.59 μg/L to 2.0059 g/L, migratory factors such as the rate of movement, the extent of the pathway, and the straightness of trajectory of Artemia tended to reduce. Hormesis was observed at 2.0059 mg/L Hg2+ and the migratory factors of Artemia were significantly increased. Interestingly, hormesis was also observed in the analysis of turning angle distribution. Shrimp moved with a large angle at a high concentration of Hg2+, showing a peculiar trajectory like that of hovering. Similar results were also observed in real seawater samples. In conclusion, the multi-tracking system for the analysis of behavioral endpoints of Artemia can be used as a fast, simple, repeatable, and easily interpretable testing method to provide more information regarding the toxicity of chemical substances.