Water is critical to survival, yet free-standing water is often rare in deserts and seasonally dry environments. Thus, many dry-adapted species utilize either metabolic (that produced from metabolism) or dietary (that found in food) water to meet their hydric needs. It is suspected that desert reptiles can fulfill their hydric needs solely through dietary water intake. However, food consumption does not improve the hydration state of Gila monsters (Heloderma suspectum), a binge-feeding desert lizard, and meal consumption by snakes leads to increased voluntary drinking. Therefore, we predicted that meal consumption would not improve hydration state in dehydrated western diamondbacked rattlesnakes (Crotalus atrox). We found no significant difference in the change in plasma osmolality between moderately dehydrated snakes that consumed a meal and those that did not. In fact, snakes that received a meal reached severe dehydration more than a week sooner than snakes that did not receive a meal. Additionally, consuming a meal when severely dehydrated did not reduce plasma osmolality, whereas severely dehydrated snakes provided with water ab lib. returned to a normosmotic state. These results provide the most convincing evidence that carnivorous desert reptiles likely rely on free-standing water to fulfill their hydric needs. These species have thus had to adapt to sporadic water availability through minimizing water loss and tolerating considerable variation in plasma osmolality.

中文翻译：

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响尾蛇必须喝：进餐并不能改善水合状态。

水对于生存至关重要，但是在沙漠和季节性干燥的环境中，常备水通常很少。因此，许多适应干旱的物种利用新陈代谢（由新陈代谢产生的水）或饮食（在食物中发现）的水来满足其水需要。怀疑沙漠爬行动物仅通过饮食中的水就能满足其体内的水需要。但是，食用食物并不能改善暴饮暴食的沙漠蜥蜴-吉拉怪兽（Helodermadermatum）的水合​​状态，而蛇食会导致自愿饮酒的增加。因此，我们预测膳食消耗不会改善脱水的西部菱纹响尾蛇（Crotalus atrox）的水合状态。我们发现进食与未进食的中度脱水蛇之间血浆渗透压的变化没有显着差异。实际上，进食蛇的时间比未进食蛇的时间快了一周以上。另外，在严重脱水时进餐并不能降低血浆渗透压，而严重脱水的蛇则具有水溶性。回到正常状态。这些结果提供了最有说服力的证据，表明食肉的沙漠爬行动物很可能依赖独立的水来满足其水需要。因此，这些物种必须通过最大程度地减少水的流失并容忍血浆渗透压的变化来适应零星的水供应。进餐的蛇比未进餐的蛇严重脱水一周以上。另外，在严重脱水时进餐并不能降低血浆渗透压，而严重脱水的蛇则具有水溶性。回到正常状态。这些结果提供了最有说服力的证据，表明食肉的沙漠爬行动物很可能依赖独立的水来满足其水需要。因此，这些物种必须通过最大程度地减少水的流失并容忍血浆渗透压的变化来适应零星的水供应。进餐的蛇比未进餐的蛇严重脱水一周以上。此外，在严重脱水的情况下进餐并不能降低血浆渗透压，而严重脱水的蛇具有一定的水分吸收能力。回到正常状态。这些结果提供了最有说服力的证据，表明食肉的沙漠爬行动物很可能依赖独立的水来满足其水需要。因此，这些物种必须通过最大限度地减少水的流失并容忍血浆渗透压的变化来适应零星的水供应。这些结果提供了最有说服力的证据，表明食肉的沙漠爬行动物很可能依赖独立的水来满足其水需要。因此，这些物种必须通过最大限度地减少水的流失并容忍血浆渗透压的变化来适应零星的水供应。这些结果提供了最有说服力的证据，表明食肉的沙漠爬行动物很可能依赖独立的水来满足其水需要。因此，这些物种必须通过最大限度地减少水的流失并容忍血浆渗透压的变化来适应零星的水供应。