Vol. 46 No. 5, 2007
Thermal Tolerance and Altitudinal Distribution of Three Trimeresurus Snakes (Viperidae: Crotalinae) in Taiwan
Szu-Mien Huang, Shu-Ping Huang, Yi-Huei Chen, and Ming-Chung Tu*
Department of Life Science, National Taiwan Normal University, 88 Ting-Chow Rd., Sec. 4, Taipei 116, Taiwan
Szu-Mien Huang, Shu-Ping Huang, Yi-Huei Chen, and Ming-Chung Tu (2007) We measured and compared the acute thermal tolerances of a high-altitude pit viper, Trimeresurus gracilis, with that of its lowland congeners, T. mucrosquamatus and T. s. stejnegeri,
to test whether their thermal tolerances are limiting factors
determining their altitudinal distributions. The critical body
temperatures, both the summer critical thermal maximum (CTMax) and the
winter critical thermal minimum (CTMin), of these 3 species were
measured after 2 wk of acclimation at 3 temperature regimes (10, 20,
and 30°C). We discovered that (1) both the CTMin and CTMax of these 3 Trimeresurus snakes increased with increasing acclimation temperatures; (2) the lowest CTMin values of T. gracilis and T. mucrosquamatus did not significantly differ from each other, and both of them were significantly higher than that of T. s. stejnegeri; and (3) the CTMax values of these 3 Trimeresurus
snakes did not significantly differ from each other. Overall, we did
not find a clear relationship between acute thermal tolerances and
altitudinal distributions of these 3 Trimeresurus species; hence, their acute thermal tolerances should not be limiting factors in determining their altitudinal distributions.
Key words: Pit viper, Critical thermal maximum, Critical thermal minimum, altitude, Temperature.
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