Effect Of Incubation Tem Perature On Hatchling Traits And Immunity Of Chinese Soft-sheiled Turtle (Pdodiscus Sinensis)

With the global warming and harsh climate anomalies, hatching period and morphology of the larvae could be deeply influenced by temperature. Researches on the immunity of new hatchings were scarce. In this study, we incubated eggs of Chinese soft-shelled turtle(Pelodiscus sinensis) in different temperatures to illustrate dirrerent morphology and immunity of hatchlings. First, we designed an experiment which contained four temperature treatment groups. Eggs was incubated in 28℃, fluctuate temperature 28±2℃, 26-30℃(changed the incubation temperature at embryo development stage 17), and 30-26℃(changed the incubation temperature at embryo development stage 17). Weight and body height of hatchlings were significantly affected by incubation temperature, but carapace longth and width of hatchlings were not affected by incubation temperature. Hatchlings from fluctuating temperature 28±2℃ posessed the heaviest weight. Hatchlings from 26-30℃ and 28℃ had the same weight. Hatchlings from 30-26℃ were lightest. Hatchlings from 30-26℃ posessed the hightest body height,following with hatchlings from 28±2℃, 28℃ and 26-30℃. We challenged hatchlings from four groups to illustrate immunity difference. The cumulative mortality rate of hatchlings a fter bacteria challenge showed that immunity of hatchlings from 28±2℃ was much better than hatchlings from 26-30℃, 30-26℃ and 28℃. We also analyzed serum acid phosphatase and alkaline phosohatase of hatchlings before and after bacteria challenge, but the enzyme activities were not consistent with immunity.Second, we designed another experiment. The eggs of Chinese soft-shelled turtles were treated by heat waves with 28℃ as control temperature. Incubation period of low frequency heat waves treatment group(24/38℃ high temperature twice a week) was longer than incubation period of control treatment group(28℃) and the high frequency heat waves treatment group(20/38℃ high temperature once per day). The hatching rate of low frequency heat waves treatment group was higher than the other two groups. However, the high frequency heat waves treatment group(20/38℃ high temperature once per day) posessed the lightest weight. After bacteria challenge,the LD50 analysis results showed that the immunity of high frequency heat waves treatment group was lowest among three groups, and the low frequency heat waves treatment group poessed the highest immunity. We also analyzed serum acid phosphatase and alkaline phosohatase of hatchlings before and after bacteria challenge, but the enzyme activities were not consistent with immunity as well in this experiment.