Abstract: We measured the levels of plasma corticosterone (CORT) from three samples of Pelodiscus sinensis (12, 18 and 24 months after hatching) under normal growth condition. The effects of different temperatures (10, 20 and 33 ℃) on CORT levels, immune biochemical indicators and antibacterial effects were examined, with (28 ± 2) ℃ (constant temperature) as control. The results showed a significant difference in CORT levels between 12 and 24month-old individuals (P<0.05). The CORT level in each group showed a tendency of first rising and then decreasing over time. The CORT level in the 10 ℃ and 20 ℃ groups was significantly different from the control after treated for four and six hours (P<0.05). The enzyme activity and protein content of each temperature treatment first increased and then decreased over time. There was no significant difference compared to the control (P>0.05). The antibacterial effect of plasma was negatively correlated with CORT level. Our results indicated that sudden changes in temperature caused stress response for P. sinensis, which increased the CORT level, changed the immune biochemistry, and reduce the antibacterial effect, with a negative effect on organism immunity.

Key words: landscape index, landscape ecology, landscape change., ecosystem integrity assessment