The Role of Behavioral Thermoregulation in the Growth Energetics of the Toad, Bufo Boreas
The Role of Behavioral Thermoregulation in the Growth Energetics of the Toad, Bufo Boreas
复制标题
行为温度调节在蟾蜍生长能量中的作用
DOI：
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发表时间：
1973
期刊：
影响因子：
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通讯作者：
Pamela Chelgren
中科院分区：
文献类型：
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作者：
H. Lillywhite;P. Licht;Pamela Chelgren
新变态的西方蟾蜍，蟾蜍boreas，是昼夜活跃和体温调节的行为利用可用的微环境，包括暴露在太阳辐射。在实验室里，蟾蜍通过在白炽灯下晒太阳来调节体温，当它们被放置在光热梯度内时。晒太阳取决于喂养，当食物被扣留时，个体放弃可用的热源并承担较低的体温。根据实验室和自然界中的动物测定，喂养个体的优选温度为26-27摄氏度左右;禁食动物保持在15-20摄氏度之间。在各种温度下测量了自由采食的幼蟾蜍的生长。能量摄入（食欲），线性增长，体重增加，和总转换效率都是最大的在27摄氏度和几乎相同的蟾蜍允许在光热梯度thermoregulate。特定体重的能量摄入，特定体重的增长，总转换效率随年龄的增长而下降。饥饿的蟾蜍在温度梯度中的存活时间比保持在恒定的27摄氏度的蟾蜍要长。在10-33摄氏度的范围内，新陈代谢随着体温的增加而增加。我们得出的结论是，这种陆生外温动物已经进化出一种行为的温度调节机制，最大限度地提高增长和经济利用的能量。小蟾蜍的昼夜行为模式（与更严格的夜间成年蟾蜍相比）可能已经进化到最大限度地提高年轻个体的生长速度，从而缩短了它们达到成年体型的时间。
Newly metamorphosed Western toads, Bufo boreas, are diurnally active and thermoregulate by the behavioral exploitation of available microenvironments including exposure to solar radiation. In the laboratory, toads thermoregulate by basking beneath incandescent lamps when placed within a photothermal gradient. Basking depends on feeding, and when food is withheld, individuals abandon the available heat source and assume lower body temperatures. The preferred temperature of feeding individuals is around 26—27 degrees C as determined from animals both in the laboratory and in nature; fasting animals remain between 15—20 degrees C. Growth of young toads with ad libitum food supply was measured at a variety of temperatures. Energy ingestion (appetite), linear growth, weight increase, and gross conversion efficiencies were all maximal at 27 degrees C and were nearly identical to that of toads allowed to thermoregulate in a photothermal gradient. Weight—specific energy ingestion, weight—specific growth, and gross conversion efficiency decreased with age. Survivorship of starved toads in a thermal gradient was prolonged over that of toads maintained at a constant 27 degrees C. Metabolism increased with body temperature over the range 10—33 degrees C. We have concluded that this terrestrial ectotherm has evolved a behavioral thermoregulatory mechanism which maximizes growth and economic utilization of energy. The diurnal behavior patterns of small toads (compared with the more strictly nocturnal adults) may have evolved to maximize the growth rates of younger individuals, thus shortening their time to adult size.