Stress responses in sub-yearling great sturgeon to the air exposure

This study was conducted the effect of stress on blood glucose and cortisol levels in cultured great sturgeon. Blood sampling was done and then water level decreased to the half in experimental tanks. The fish were exposed in that situation and second blood sampling was taken after 6 hours. Glucose and cortisol concentrations were measured by glucose oxidase method and Radioimmunoassay (RIA), respectively. The results showed that average of cortisol concentration reached from 10.8 ± 3.3 to 14.6 ± 9.0 ng ml-1 (P < 0.05). Indeed, average of glucose concentration was 56.4 ± 12.0 pre-stress exposures and reached to 111.6 ± 17.5 mg dl-1 post-stress (P < 0.05). Stress is most often associated with a negative perspective. We recommend for increasing efficiency in rearing, should avoid of stressors possibly that it needs to right management on rearing practice and this action causes to increase in production, fish welfare, restoration and economic efficiency.