宁波地区黑斑蛙的繁殖生态和产卵地选择

Breeding Ecology and Oviposition Site Selection of Black-spotted Pond Frogs (Rana nigromaculata)in Ningbo, China

黑斑蛙是我国分布最广的两栖动物之一,但目前有关其繁殖生态和产卵地选择还所知甚少,而且多局限于定性描述。2004—2006年在宁波地区黑斑蛙的繁殖期,对黑斑蛙的繁殖生态研究分析表明,该蛙在繁殖期的种群密度为0.0903±0.0029只/m(n=11);该蛙是雌雄二形性的蛙类,雌性蛙类的体重和体长都显著大于雄性;该蛙窝卵数的变化幅度较大(1546—7897个),平均窝卵数为4643.04±235.96个(n=50);卵径范围为1.50—1.74mm,平均卵径大小为1.6050±0.0046mm(n=226)。对黑斑蛙产卵地选择的研究结果表明,产卵地在水域比率、裸地比率、植被盖度、水深、水温和水的透明度等方面与随机样方不同;该蛙偏爱在水域比率和植被盖度较高的生境产卵,而避免在水体较深的生境产卵。为了更好地保护黑斑蛙的产卵栖息地,今后应优先保护水域比率和植被盖度较高而水体不深的生境。

The Black-spotted pond frog （Rana nigromaculata ） is one of the most widely distributed species in China. However, to date there are few qualitative descriptions of their breeding ecology and oviposition site selection. Such issues have important implications for establishing more effective conservation and protection management strategies for this species. From 2004 to 2006, we studied R. nigromaculata in Ningbe, China, to quantify their breeding ecology and oviposition site selection. Analyses of breeding ecology showed that： （1） mean frog density in the breeding season was 0.0903 ± 0.0029/m （n = 11） （all data are listed as Mean ± SE）; （2） R. nigromaculata is a sexually dimorphic species, with females significantly larger than males in beth body weight and snout-vent length; （3） the clutch size averaged 4643.04 ± 235.96 eggs （range 1 546 -7 897, n = 50） ; and （4） the egg size ranged from 1.50 to 1.74 mm in diameter, with an average egg size of 1.6050 ± 0.0046 mm （n = 226）. Oviposition sites differed significantly from randomly selected sites in percentages of water, bare ground and vegetation cover, water depth （cm）, water temperature （℃） and water turbidity. Rana nigromaculata preferred microhabitats with higher percentages of water and vegetation cover, while it avoided microhabitats with deeper water. The results suggest that microhabitats with higher percentages of water and vegetation cover, but not deeper water, should be priorities for protection to conserve the breeding habitats of R. nigromaculata.