SIMULATED TRANSPORT TEMPERATURE CHANGE ON STRESS RESPONSE AND ANTIOXIDANT CAPACITY OF JUVENILE CHINESE SOFT-SHELLED TURTLE PELODISCUS SINENSIS

The Chinese soft-shelled turtle (Pelodiscus sinensis) is a special aquaculture species in China, known for its sensitivity to temperature changes. Stress response is easy to occur during long-distance transportation such as off-site feeding and cross-domain sales, which has adverse effects on the product quality and health. Suitable temperature can alleviate transportation stress. In order to investigate the effects of temperature change on stress response and antioxidant capacity during simulated transportation of juvenile P. sinensis, the experiment was carried out by changing the rotational speed and temperature of the constant temperature and humidity shaker to simulate the transportation process. In this study, Chinese soft-shelled turtles with initial weight of 200±10 g were simulated to be transported at high temperature (T1, 32℃) and low temperature (T2, 20℃) for 12h, and then left to recover at ambient temperature of 32℃ for 12h after transportation. The results showed that during the transportation stage, compared with group T1, the relative abundance of mRNA of liver heat shock protein (Hsp90, Hsp70), glutathione peroxidase 4 (Gpx4), nuclear factor E2-related factor 2 (Nrf2), and plasma cortisol (COR) in group T2 were significantly reduced (P<0.01). Compared with T1 and T2 in the transportation stage, the relative abundance of mRNA of Hsp70, manganese superoxide dismutase (Mnsod), glutathione peroxidase (Gpx1, Gpx4) in the liver and plasma COR content in the recovery stage were significantly reduced (P<0.05). In the recovery stage, compared with group T1, the relative abundance of mRNA of Hsp70, Hsp90, Gpx1, Gpx4, Nrf2, and SOD enzyme activity of group T2 were significantly reduced (P<0.05), while the proportion of type Ⅰ collagen and the ratio of type Ⅰ to type Ⅲ collagen in the calipash tissue were significantly increased (P< 0.01). The results showed that simulated high-temperature transportation causes oxidative stress in Chinese soft-shelled turtles. Low-temperature transportation and recovery were beneficial to alleviate stress response, oxidative damage, and maintain the calipash form during transportation. This study provides scientific reference for establishing reasonable transportation regulations in the production of Chinese soft-shelled turtles.