博士 / 國立臺灣大學 / 動物學研究所 / 90 / Sauter''s frog, Rana sauteri Boulenger, 1909 in the centro-western part of the Central Mountain Range of Taiwan at elevations of 300 m to 2360 m showed obvious altitudinal clines in reproductive and life cycle traits. With the increase in elevation, the breeding season, the period of calling, aggregation and egg deposition of mature frogs, shifted from fall and winter (October to December) to spring (May), while the breeding period decreased but the larval period increased. Also, adult females of high elevation were larger and produced smaller clutch size but larger eggs and tadpoles. The temperature experiment showed that low temperature in winter at high elevations and high temperature in summer at low elevations may be the primary environmental factors that define the breeding success of the species. The patterns of growth and development of tadpoles of R. sauteri at Chitou (1,100 m) and Mienyueh (2,350 m) were investigated. In Chitou, tadpoles of different developmental stages can be found from December to March, indicating that the growth and development of tadpoles are not synchronized. In Mienyueh, the majority of tadpoles ceased to develop after reaching Phase 2 in August even though they did not stop growing until December. Tadpoles resumed growth and development at the following spring, and reached metamorphosis by June. It appears that tadpoles ceased to develop early enough so that they could channel a greater proportion of energy into growth to get larger size for better survival rate in cold winter. In addition, tadpoles in Mienyueh ceased to develop early enough so that they could overwinter with Phase 2, the more simple type, to reduce the risk of limb frostbite and larval mortality during the extreme cold temperatures. Our results suggest: 1) R. sauteri was long-term selected by the environment, resulted in the populations of high elevation bred in spring and the populations of low elevation bred in fall and winter to increase the growth and survival rate of tadpoles, 2) the different patterns of larval growth and development between populations to increase the rate of metamorphosis, are adaptive strategies for the best survival of tadpoles in the mountains of Taiwan.
| Identifer | oai:union.ndltd.org:TW/090NTU00312006 |
| Date | January 2002 |
| Creators | Su- Ju Lai, 賴肅如 |
| Contributors | Yao- Sung Lin, Yeong- Choy Kam, 林曜松, 關永才 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 80 |
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