Physical and Physiological Costs of Reproduction in Watersnakes
Physical and Physiological Costs of Reproduction in Watersnakes
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DOI：
10.1643/cp-15-347
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发表时间：
2016-09
期刊：
影响因子：
2.6
通讯作者：
J. Chamberlain;M. Gifford
中科院分区：
文献类型：
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作者：
J. Chamberlain;M. Gifford
估计繁殖成本对于理解当前和未来繁殖成功之间的权衡至关重要，这是生活史理论中的一个关键预测。理论上，每次生育成本的增加会降低未来的生育能力。此外，成本可能会随着个人的成长而变化，从而改变这种权衡的性质。测量繁殖过程中雌性动物运动能力的变化是衡量雌性动物繁殖成本的一种有效方法。我们测量了雌性菱背青蛇（Nerodia rhombifer）在怀孕期间和怀孕后的游泳速度，以确定是否有运动能力的损失。然后，我们将这些速度与生殖负担（估计相对离合器质量）和身体大小的措施，以调查如果增加生殖投资和身体大小改变运动能力和随后的繁殖成本。雌蛇在怀孕期间比怀孕后游得慢。较大的相对离合器质量导致较慢的游泳速度在怀孕期间。此外，较短的个人表现出更大的游泳速度下降，这表明较小的个人繁殖成本更高。最后，我们证明，额外的成本，运动能力可能会产生的女性由于体重减轻怀孕期间携带生殖材料的负担。
Estimating the cost of reproduction is pivotal to understanding the trade-off between current and future reproductive success, a key prediction in life-history theory. Increases in the cost of each reproductive attempt theoretically reduce future reproductive ability. Further, costs may change as individuals grow thus changing the nature of this trade-off. Measuring changes in female locomotor ability during reproduction has been one effective method to measure the cost of reproduction for females. We measured female Diamond-backed Watersnake (Nerodia rhombifer) swimming speed during and after pregnancy to determine if there was a loss of locomotor ability. We then correlated these speeds with measures of reproductive burdening (as estimated by relative clutch mass) and body size to investigate if increased reproductive investment and body size changed locomotor ability and subsequent cost of reproduction. Female snakes swam slower during pregnancy than after. Larger relative clutch masses resulted in slower swimming speeds during pregnancy. Further, shorter individuals showed a greater decrease in swimming speed suggesting a greater cost of reproduction for smaller individuals. Lastly, we demonstrated that additional costs to locomotor ability may be incurred by the female due to weight loss during pregnancy from carrying the burden of reproductive material.