Matsuki Takashi, Matsui Masafumi
Graduate School of Human and Environmental Studies, Kyoto University, Yoshida , Sakyo-ku, Kyoto 606-8501, Japan.
Zoolog Sci. 2011 Mar;28(3):175-9. doi: 10.2108/zsj.28.175.
The age structure of breeding females of Hynobius nebulosus has not been studied sufficiently. We estimated the ages of 76 individuals from a population in Kyoto by using skeletochronology. The mean age and snout-vent length (SVL) of this population were 4.6 years and 55.7 mm, respectively. It was estimated that the youngest females breed two years post hatching at a mean SVL of 46.5 mm, but a larger number of individuals begins breeding at three years and a mean SVL of 52.2 mm. Because most males also start to breed at three years, there seems to be no gender difference in the timing of sexual maturation. The age of the oldest female was estimated to be 11.8 years. It is possible that the life history of H. nebulosus is characterized by early maturation and arrested growth, and short longevity.
日本林蛙繁殖期雌蛙的年龄结构尚未得到充分研究。我们通过骨骼年代学方法估算了京都一个种群中76只个体的年龄。该种群的平均年龄和吻肛长（SVL）分别为4.6岁和55.7毫米。据估计，最年轻的雌蛙在孵化后两年开始繁殖，平均吻肛长为46.5毫米，但更多个体在三年时开始繁殖，平均吻肛长为52.2毫米。由于大多数雄蛙也在三年时开始繁殖，所以性成熟时间似乎没有性别差异。估计最年长雌蛙的年龄为11.8岁。日本林蛙的生活史可能具有早熟、生长停滞和寿命较短的特点。
