Optimization and calibration of behavioural tests on different species of planaria for ecotoxicological studies

Freshwater planarian are emerging as a valuable in vivo model for (eco) toxicological studies, but the lack of harmonization of procedures between laboratories remains a challenge. This study aimed to optimize, automate and select the best behavioural tests and analyse the potential of different planarian species as models for toxicological assessment. We implemented four tests: exploration, photomotor response, Tapping and Planarian Light Dark Test, on different planaria species using the DanioVision system. We conclude that the exploration assay performed in 24 well-plate at 10,000 lux is the one that is robust and reliable for toxicological studies with planaria. Dugesia japonica and Schmidtea mediterranea have proved to be sensitive models for toxicological screening of organophosphorus pesticides through behavioural analysis. Under necessary experimental conditions, the motility baseline in controls, for both species allowed the detection of behavioural changes, making both good models for behavioural testing in (eco) toxicological context.

Automated summary

Freshwater planarian are important models for (eco) toxicological studies, but the lack of procedure harmonization between laboratories is a challenge. This study optimized, automated, and selected the best behavioral tests, and identified Dugesia japonica and Schmidtea mediterranea as sensitive models for toxicological assessment of organophosphorus pesticides. The exploration assay at 10,000 lux in a 24 well-plate was found to be robust and reliable for toxicological studies with planaria.