抄録
Using an image analyzer, behavioral changes of the freshwater shrimp, Paraiya compressa improvisa, were investigated within a controlled laboratory setting on the Sakura River, Japan. Increasing shrimp mobility corresponded to sublethal concentrations of pesticides detected in river water during the rice-cultivating season. The chemicals causing high shrimp mobility were removed by filtration with an activated carbon filter. Shrimp mobility in the untreated river water was 3 to 10 times higher than in the filtered river water, The growth rate of shrimps, measured over one month in the summer, was lower for those in the unfiltered river water than in the filtered river water. The results suggest that an image analyzer is a useful tool biological early warning system to monitor chemicals in river water, and behavior analysis of P.compressa improvisa can detect sublethal effects in an actual environment.
