骨龄学方法测定中国水蛇的年龄

SKELETOCHRONOLOGICAL AGE ESTIMATES FOR THE Enhydris chinensis

取不同体长的中国水蛇 (Enhydrischinensis)标本 4 4条 ( 2 9♀♀ ,14♂♂ ,1胎蛇 ) ,剥取心脏附近的椎骨 5枚 ,按常规骨骼磨片方法磨制椎骨中部的横切片 ,于低倍光学显微镜下观察。可以看到 ,磨片上有清晰的生长层 ,年老的个体更典型。用椎骨半径对生长层厚度的回归方程和vonBertalanffy的生长方程式估算在骨骼生长过程中被再吸收而消失了的生长层。结果 ,4 4条标本的年龄范围是 0～ 11 2龄。年龄与体全长雌体成对数函数回归关系 ,回归方程是 :L (体全长 ) =2 72 4 +64 7 2lgA (年龄 ) ;相关系数r =0 95 98;雄体则成直线回归关系 ,回归方程是L =3 17 5 +4 6 3A ,r =0 95 2 7;显著性检验表明 ,雌、雄蛇的年龄对体全长均显著相关 (P <0 0 1)。最小性成熟年龄雌性是 1 8龄 ,雄性是 1 0龄。

Enhydris chinensis (29 females,14 males,1 focus) got in the market were used in the examination of the middle cross sections of vertebrae ground in an ordinary abrasive disc way (taking five vertebraes near the heart).Under a microscope their annual rings were observed.We can see that the older the snakes are,the clearer their rings are.Correctness of the resorbed growth layers in the process of the skeleton growth by the regression equation of vertebrae radius vs growth layer width and von Bertalanffy growth equation indicates that the ages of the Enhydric chinensis specimens range from 0-11 2 years,their ages and their body length form a ringe relationship,the regression equation of the females is L (total length)=272 4+647 2lg A (year), r =0 9598, P <0 01;that of the males being L =317 5+46 3 A (year), r =0 9527, P <0 01,and the earliest sexual maturity of the females appears at the age of 1 8 years,that of the males at 1 0 year.