圈養狀況下之斑腿樹蛙生活史

Life History of the Spot-Legged Tree Frog Polypedates megacephalus in Captivity

爲了解斑腿樹蛙（Polypedates megacephalus）的生活史特性，2007年10月我們從馬祖地區採集了3隻雄性及2隻雌性斑腿樹蛙攜回實驗室進行爲期1年的圈養與觀察。這些雌蛙在2008年3-8月間，共產下10堆卵泡，每堆卵泡平均約有639個卵。在16.6-29.3℃的環境溫度下，卵約3-8天可孵出，各卵泡的孵化時間與當時的室外溫度呈現負相關，其孵化率約爲92.3%。在19.5-29.8℃的環境溫度下，蝌蚪從孵化到Gosner第37發育期的時間平均爲36.1天，而蝌蚪發育到Gosner第42發育期的時間平均爲46.6天，蝌蚪的變態率平均爲3.3%。雌雄蛙在體型及體色上均呈現明顯的二型性，雌性斑腿樹蛙的體型（吻肛長7.4±0.9cm、體重32.6±9.1g）大於雄蛙（5.0±0.3cm、9.8±3.6g）的體型；雌蛙體色呈暗褐色，而雄蛙體色會隨外界飼養環境的改變而轉換，其顏色可爲黃色、淺褐色或暗褐色。依據趾骨鑑齡法判別該2隻雌蛙的年齡均爲7歲，其他5隻雄蛙的年齡在3-6歲間。此外，文中也將斑腿樹蛙與台灣其他樹蛙的生態資料一併進行討論。

Three males and two females of the spot-legged tree frog Polypedates megacephalus were collected from the Matsu islands off the coast of Mainland China in October 2007. They were kept in captivity in the laboratory for a year and their life-history was observed. The females deposited 10 clutches of foam nests at an average of 639 eggs per clutch from March to August 2008. The eggs hatched 3-8 days after the deposition at 16.6-29.3℃. The hatching periods were negative correlated to the ambient temperatures. The hatching rate was 92.3%. At 19.5-29.8℃ the hatchlings took an average of 36.1 days to reach Gosner's stage 37 and 46.6 days to stage 42. The mean metamorphic rate was 3.3%. There was sexual dimorphism in size and coloration. The adult females were larger (SVL, 7.4±0.9 cm; weight, 32.6±9.1g) than the adult males (5.0±0.3 cm and 9.8±3.6g). The females were darkish brown in color while the male s color varied widely: yellow, light brown or darkish brown depending on the surrounding environments. According to skeletochronology, the two females examined were 7 years old and the five males were 3 to 6 years old. Also, ecological traits of P. megacephalus and other tree frogs in Taiwan were discussed.