LAUSR

This study examined changes in locomotor activity of the rainbow trout (Oncorhynchus mykiss) juveniles exposed to sublethal concentrations of hexavalent chromium (Cr6+) (as a single pollutant) and landfill leachate (as an complex mixture of mainly organic compounds, including trace amounts of metals). Fish were first examined for baseline behavior patterns for 3 h to determine the appropriate duration of acclimation and the control level. The average velocity of fish was found to be the most informative among other endpoints throughout the 3 h long acclimation. Under the effect of both test substances, fish locomotor activity significantly increased after 5 min reaching maximum values after 10 min of exposure. The juveniles exposed to leachate were more responsive than those exposed to Cr6+. However, in this study we did not succeed in identifying pollutants from the elicited fish behavioral response patterns.