Hydric balance and locomotor performance of an anuran (Rhinella marina) invading the Australian arid zone
Hydric balance and locomotor performance of an anuran (Rhinella marina) invading the Australian arid zone
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入侵澳大利亚干旱区的无尾蜥蜴（Rhinella marina）的水分平衡和运动性能
DOI：
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
R. Shine
中科院分区：
文献类型：
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作者：
R. Tingley;M. Greenlees;R. Shine
入侵物种经常遇到的环境条件远远超出了他们的本土地理范围，从而提供了理想的模型系统，探索新的非生物挑战的反应。在澳大利亚，入侵的甘蔗蟾蜍Rhinella marina已经在比其本土范围内发现的干旱地区定居。这些新环境的殖民化是否伴随着生理和/或运动性能的变化？我们测量了蒸发失水率，水增益，和干燥对运动性能的甘蔗蟾蜍从两个入侵前线：一个中（湿干热带）和一个干旱（半沙漠）。这两个群体的差异很大。与直觉相反（但与其他蟾蜍种群从梅西奇与干旱地区之间的种内比较一致），从梅西奇种群蟾蜍的蒸发失水率较低（不高）。然而，干旱区蟾蜍获得水更迅速地通过其腹侧表面，和水的损失和增益率是高度相关的个别蟾蜍从干旱区人口。在实验室驯化蟾蜍从半干旱区的水交换率没有不同的自由放养同种从同一人口，这表明，中东和半干旱蟾蜍之间的分歧反映了基因的变化，发生在物种的澳大利亚入侵。梅西奇和半干旱蟾蜍表现出类似的运动性能（耐力，每跳距离）时，完全水合，但运动性能下降得更快，干燥的梅西奇蟾蜍。因此，在甘蔗蟾蜍入侵澳大利亚的短短（数十年之久）的时间跨度内，在抵御干燥条件的能力方面存在着巨大的种群差异。如果我们要准确地预测入侵生物的分布（以及由此产生的影响），我们就需要在风险评估计划中纳入适应潜力。
Invasive species often encounter environmental conditions well outside those found in their native geographic ranges, and thus provide ideal model systems with which to explore responses to novel abiotic challenges. Within Australia, the invasive cane toad Rhinella marina has colonized areas that are considerably more arid than those found within its native range. Has the colonization of these novel environments been accompanied by shifts in physiology and/or locomotor performance? We measured rates of evaporative water loss, water gain, and effects of desiccation on locomotor performance of cane toads from two invasion fronts: one mesic (the wet-dry tropics) and one arid (the semi-desert). The two populations diverged substantially. Contrary to intuition (but consistent with intra-specific comparisons between other toad populations from mesic vs arid areas), rates of evaporative water loss were lower (not higher) in toads from the mesic population. However, arid-zone toads gained water more rapidly through their ventral surfaces, and rates of water loss and gain were highly correlated within individual toads from the arid-zone population. Rates of water exchange in laboratory-acclimated toads from the semi-arid zone did not differ from those of free-ranging conspecifics from the same population, suggesting that divergences between mesic and semi-arid toads reflect genetic changes that have occurred during the species’ Australian invasion. Mesic and semi-arid toads showed similar locomotor performance (endurance, distance per hop) when fully hydrated, but locomotor performance declined much more rapidly with desiccation in the mesic toads. Thus, within the short (decades-long) timespan of the cane toad's Australian invasion, there has been substantial population divergence in the ability to withstand desiccating conditions. If we are to accurately predict the distributions (and hence impacts) of invading organisms, we will need to include adaptation potential in risk assessment schemes.
影响因子：
1.5
作者：
Lee, Carol Eunmi;Remfert, Jane Louise;Chang, Yu-Mei
通讯作者：
Chang, Yu-Mei