多疣壁虎的繁殖生态研究

THE REPRODUCTIVE ECOLOGY OF THE GECKO GEKKO JAPONICUS

多疣壁虎(Gekko japonicus)是一种季节性繁殖的爬行动物,性腺活动状态在不同的季节有显著的差异。成年雌体在冬眠结束后的4月初卵巢开始增大,野外产卵期一般在5月下旬至8月上旬。一个繁殖期平均产卵1.8窝,每窝恒定两枚。每窝卵重与个体大小之间存在着显著的正相关,大个体的产卵频率亦较高。雄体的精巢重量和大小的月间差异显著,但变化不及雌体的卵巢显著。雌体的繁殖期可以被环境温度所改变。繁殖效力用每窝卵干、湿重及能值与雌体干、湿重及能值的比值估算。

The annual reproductive cycle of the gecko Gekko japonicus was determined.Females exhibited ovarian growth following early emergence. Ovarian mass and follicle size were maximum in spring, decreasing through the egg-laying period and reaching minimal mass and size in August. The first clutch was laid in late May or early June. Oviposition continued until early August.Individuals of the gecko matured after the age of three years. Females could lay eggs at the mean SVL of 62.3mm. One to three (average 1.8) clutches, with two eggs each, were oviposited annually. Clutch weight and clutch frequency were positively correlated with females' SVLs. There was no significant difference in clutch weight between the first clutch and the second clutch.In contrast to females, changes in testicular mass and size were not as significant as ovarian changes, though monthly changes in testicular mass and size were statistically significant.The timing of reproductive cycle of the females could be changed by ambient temperature. Prolonged exposure to higher temperature (26℃) in the fall promoted females entering the next reproductive cycle, and exposure to higher temperature (26℃) in late hibernation period increased ovarian index.Reproductive effort was estimated by using clutch to body wet weight ratio, clutch to body dry weight ratio, clutch to body ash-free caloric ratio and clutch to body ash uncorrected caloric ratio.