To evaluate the genotoxic, physiological and immunological effects of short-term acute low temperature
stress on the Pacific white shrimp, Litopenaeus vannamei, we rapidly transferred shrimp from tanks at
23±2 °C to aquaria at the same temperature (controls) or 12±2 °C for 12 h. Changes in the shrimp hemocyte
respiratory burst activity and DNA damage were examined during and after exposure to the temperature
stress using flow cytometry and the comet assay, respectively.We alsomonitored changes in the total hemocyte
count, malondialdehyde levels, total protein concentration and osmolality in shrimp plasma. The results
show that hemocyte respiratory burst activity, malondialdehydes levels and hemocyte DNA damage in the
plasma all increased significantly after exposure to 12±2 °C for 3 h. In contrast, total hemocyte count, total
protein concentration and osmolality in the plasma decreased compared to the controls. We conclude that
acute lowtemperature can induce oxidative stress, DNA damage, lipid peroxidation and changes in osmolality in
L. vannamei.