温度对中华条颈龟孵化和性别的影响

Effects of Temperature on Incubation and Sexual Determination in Turtle Mauremys sinensis

研究了5个孵育温度（25±0．5）℃，（27±0．5）℃，（29±0．5）℃，（31±0．5）℃，（33±0．5）℃对中华条颈龟性别、胚胎发育及成活率的影响。每个温度放置30枚卵，空气相对湿度为85％～90％，基质湿度为5％～10％，重复试验2次。试验结果表明，在试验温度内，胚胎的发育速度随着孵化温度的升高而加快，孵化期缩短。在25℃时孵化成活率最低为46．2％，27℃时高达96．2％，孵出稚龟体质量、背腹甲形态发育指标显著增加，33℃时孵化率开始下降，且出现畸形龟，说明33℃的孵育温度不利于胚胎发育。在25℃时雄性率为83．3％，随着温度的升高而逐渐降低，33℃全部发育为雌性。结合温度敏感期温度转换试验，表明中华条颈龟的性别决定属于温度依赖型机制，可能属于其中的温度依赖型Ⅰ型。

The effects of temperature [（25 ± 0 .5） ,（27 ± 0 .5） ,（29 ± 0 .5） ,（31 ± 0 .5） ,and （33 ± 0 .5） ℃] and temperature conversion （from 27 ℃ to 33 ℃ and from 33 ℃ to 27 ℃） on embryonic development ,sex‐ual differentiation ,and survival of eggs were studied in turtle Mauremys sinensis incubated at a rate of 30 eggs at each temperature under relative air moisture of 85% -90% and substrate moisture of 5% -10%with duplication .The incubation period was found to be gradually declined and the incubation survival rate to be increased with the raising temperature ,the minimal incubation survival rate of 46 .2% at 25 ℃ ,and the maximal incubation survival rate of 96 .2% at 27 ℃ .The newly hatched turtle showed significant in‐crease in body weight ,length of carapace and plastron at 27 ℃ ,decline in incubation survival rate ,and in‐crease in malformation at 33 ℃ ,indicating that the turtle embryos did not develop normally at 33 ℃ .At 25 ℃ ,83 .3% of male individuals was observed in the hatched turtle ,and gradually reduced with the tem‐perature rising .At 33 ℃ ,however ,the newly hatched turtles were all female .The temperature conver‐sion showed that the mechanism of the gender determination was found to be TSD ,especially TSD Ⅰ in snapping turtle M .sinensis .