Effect of temperature change on immunochemical indexes of Eriocheir sinensis

Temperature stress could be one of the main factors for disease outbreak. This study focused on the immunological response of adult female Eriocheir sinensis to different temperature changes in order to understand how the stress modulated the immunology and defense system of E. sinensis females. Some blood immunochemical variations were used as indicators of stress measured during the 9-day experiment. The results indicated : (1) After ambient temperature reached 32°C from 20°C in 2 h and then dropped to 20°C in 30 min, the density of haemocyte cells (DHC), superoxide dismutase (SOD) activity and catalase (CAT) activity in crabs increased, then decreased, peaked at 6 h, and leveled off after day 3, while malodiadehyde (MDA) level was opposite compared with the DHC, SOD and CAT; (2) After ambient temperature decreased to 8°C from 20°C in 24 h, the DHC decreased gradually, SOD and CAT activity increased, and then decreased and peaked at day 1, while MDA level decreased, and then increased and peaked at day 3, and totally the MDA level after stress was higher than that in 0 h treatment; (3) 6 h after ambient temperature reached 32°C from 20°C in 24 h, SOD and CAT activity increased, and then decreased gradually. The DHC level after stress was lower than that in 0 h group, but the change in DHC was instable. Also the MDA content increased with time elapsed. Therefore, the results indicated that temperature changes depressed the ability of anti-oxidation, disrupted the balance of metabolism of reactive oxygen radical and reduced the resistance to disease.