Feder Martin E, Londos Pamela L
Department of Anatomy and The Committee on Evolutionary Biology, The University of Chicago, 1025 East 57th Street, 60637, Chicago, IL, USA.
Oecologia. 1984 Nov;64(3):413-418. doi: 10.1007/BF00379141.
The time until salamanders voluntarily abandoned foraging (the "water time limit") and the amount of water lost when salamanders abandoned foraging ("dehydration deficit") were determined for terrestrial plethodontid salamanders, Desmognathus ochrophaeus, foraging at various vapor pressure gradients in the laboratory. Salamander activity was correlated with the rate of water loss and was inversely related to the water time limit. Animals at 0.35-0.86 kPa vapor pressure gradients abandoned foraging and returned to moist retreats significantly sooner than animals in water-saturated air. The early retreat of animals in dry air was related in part to high rates of water loss and in part to the modest dehydration deficit (3.8%) at which animals abandoned foraging. Locomotor performance and foraging ability were unaffected by dehydration until dehydration deficits exceeded 12%. This suggests that salamanders in unsaturated air abandoned foraging at a low dehydration deficit to conserve and replenish water reserves rather than to avoid outright incapacitation or death.
在实验室中，测定了陆生无肺螈科蝾螈（Desmognathus ochrophaeus）在不同蒸气压梯度下觅食时，直到蝾螈自愿放弃觅食的时间（“水中时间限制”）以及蝾螈放弃觅食时损失的水量（“脱水亏缺”）。蝾螈的活动与失水速率相关，且与水中时间限制呈负相关。处于0.35 - 0.86千帕蒸气压梯度下的动物比处于水饱和空气中的动物显著更早地放弃觅食并返回潮湿的隐蔽处。处于干燥空气中的动物提前返回部分与高失水速率有关，部分与动物放弃觅食时适度的脱水亏缺（3.8%）有关。直到脱水亏缺超过12%，运动表现和觅食能力才受到脱水的影响。这表明处于不饱和空气中的蝾螈在低脱水亏缺时就放弃觅食，以保存和补充水分储备，而不是为了避免完全丧失能力或死亡。
