Geographic Variation In Body Size And Age Structure Of Two Frogs

Recently, the study of Rana kukunoris and Polypedates megacephalus just focused on morphology and geographic distribution, however,the basic knowledge of life history is very poor, life history of amphibians is evolved from their living environment, so the researches of different Amphibians life history is very significant for us to understanding the mechanism of species evolution.Geographic variations on the life history traits of amphibian were mainly focused on the differences in body size, age, clutch size, egg size, growth rate and so on. The main aim of this study was to explore geographic variation in body size and age structure of Rana kukunoris and Polypedates megacephalus.Life history of Rana kukunoris was studied at Ruoergai National Reserve Sichuan province and Life history of Polypedates megacephalus was studied at (Guizhou Fanjingshan National Reserve,Guangxi Dayaoshan National Reserve, Gangxi Nonggang National Reserve) from June 2009 to August 2010 respectively. The data of body size were collected by field survey, and the relevant individual's age was determined by the laboratory experiment of skeletochronology.(1) Geographic variation in body size:both the difference of length and weight between two genders and geographic variation are analyzed. Results showed that there wasn't difference between males and females in any population of Rana kukunoris, and the altitude variation wasn't obvious either. But the population of Polypedates megacephalus was quite difference, females were larger in body size than males in each population, and latitude also significantly affected adult body size, with smaller body size occuring in higher latitude, which followed converse Bergmann's rule.(2) Geographic variation in age structure:age determination in two anurans species was estimated using skeletochronlogy, and the results showed that the method was an excellent tool to determine age of our study species. For Rana kukunoris, males were generally older than females in high altitude, but the age difference between females and males was not signifibangt in lower altitude. For Polypedates megacephalus, there weren't any difference between two genders in three latitude.