University Archives

Aquatic environments are frequently exposed to both natural and anthropogenic stressors, that can negatively impact the ecosystem health. Chemical pollutants, in particular, raise concern because of their persistence and widespread distribution. We investigated the individual and combined effects of the widely used agrochemical Roundup® (active ingredient glyphosate) and the algal toxin microcystin-LR (MC-LR) on crayfish hepatopancreas cells using flow cytometry and morphological analysis. Assessing exposures to both glyphosate and algal toxins in combination enables evaluation of potential additive morphological effects of these stressors. Crayfish (N= 6 per treatment) were exposed for 7 days to 10 μg/L MC-LR, 10 μg/L glyphosate, or a combination of 10 μg/L MC-LR and 10 μg/L glyphosate). We found that exposure to MC-LR and glyphosate decreased fluorescein diacetate labeling and increased propidium iodide labeling, indicating reduced cell viability and elevated apoptosis. These data were compared with morphological analyses of hematoxylin and eosin–stained hepatopancreas tissues. Histological analysis showed that hepatopancreas tubules of exposed crayfish displayed epithelial degeneration, increased vacuolization, and dilated lumens, although combined exposure to MC-LR and glyphosate did not produce additive effects. Taken together, our findings emphasize that monitoring and regulating environmental contaminants is critical for maintaining the health of freshwater ecosystems and the organisms that rely on them.