Size-dependent temperature and desiccation constraints on performance capacity: Implications for sexual selection in a fiddler crab
Size-dependent temperature and desiccation constraints on performance capacity: Implications for sexual selection in a fiddler crab
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DOI：
10.1016/j.jembe.2012.09.009
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发表时间：
2012-12-30
影响因子：
2
通讯作者：
Levinton, Jeffrey S.
中科院分区：
文献类型：
--
作者：
Allen, Bengt J.;Rodgers, Brooke;Levinton, Jeffrey S.
繁殖活跃的男性砂招潮蟹招潮蟹pugilator经常暴露在高体温和干燥，而捍卫其他男性或显示，以吸引女性的繁殖洞穴。这些雄性通常比沼泽其他地区的雄性体型更大，部分原因是大型雄性赢得更多的比赛并且拥有更大的能量储存。我们提出了一个额外的解释：较高的热惯性和较低的质量特定的水分流失率可能会使大男性不太容易受到热应力和水化应力比小男性。以雄性招潮蟹为研究对象，研究了不同个体大小对不同温度和干燥条件下雄性招潮蟹生理和行为的影响。跑步机耐力和短跑速度增加到最大值，然后迅速下降，进一步增加T-b。中度脱水（7-10%的身体水分损失）导致运动性能显着降低，小螃蟹表现出最大的身体水分和性能能力的降低。招潮蟹似乎是敏感的体温和水合状态的潜在冲突的需求。在实验室的温度梯度，螃蟹在潮湿的沙子上选择T-B的高运动性能的能力。相比之下，在干燥的沙子上的螃蟹选择较低的T-b，这可能会使水分流失最小化，小螃蟹选择最低的T-b。除了为外温动物运动的一般模型提供经验支持外，我们的研究结果与以下观点一致：较大的个体能够更好地耐受地面上的恶劣环境条件，增加他们可以花在健身生殖活动上的时间比例，而不是在洞穴中避难。(C)2012爱思唯尔有限公司版权所有。
Reproductively active males of the sand fiddler crab Uca pugilator are routinely exposed to high body temperatures and desiccation while defending breeding-burrows from other males or displaying to attract females. Such males are generally larger than individuals in other parts of the marsh, in part, because large males win more contests and have greater energy stores. We propose an additional explanation: that higher thermal inertia and lower mass-specific water loss rates may make large males less susceptible to thermal and hydration stresses than small males. We experimentally investigated the effects of variation in body temperature (T-b) and desiccation on physiological performance and behavior of male sand fiddler crabs as a function of body size. Treadmill endurance and sprint speed increased to a maximum before decreasing rapidly with further increases in T-b. Moderate dehydration (7-10% body water loss) resulted in significantly reduced locomotor performance, with small crabs exhibiting the greatest reductions in both body water and performance capacity. Fiddler crabs appear to be sensitive to the potentially conflicting demands of body temperature and hydration state. In a laboratory thermal gradient, crabs on wet sand chose T-b's associated with high locomotor performance capacity. In contrast, crabs on dry sand selected lower T-b's that presumably minimized water loss, with small crabs choosing the lowest T-b's. In addition to providing empirical support for a general model of ectotherm locomotion, our results are consistent with the idea that larger individuals are better able to tolerate harsh environmental conditions above-ground, increasing the proportion of time they can spend engaging in fitness-enhancing reproductive activities rather than sheltering in a burrow. (C) 2012 Elsevier B.V. All rights reserved.