Department of Biology, University of Florida, Gainesville, FL 32611-8525, USA.
Florida Museum of Natural History, University of Florida, Gainesville, FL 32611-8525, USA.
J Exp Biol. 2021 Mar 5;224(Pt 5):jeb241414. doi: 10.1242/jeb.241414.
We quantified drinking behavior in three species of North American watersnakes: , which is a marine or brackish water amphibious species, and and , both freshwater amphibious species. All three species have relatively small and similar thresholds of dehydration (TH, approximately -4% loss of body mass) that elicit thirst and drinking of fresh water. These species have higher thirst sensitivity than several species of hydrophiine and laticaudine sea snakes, which are characterized by much lower TH (greater dehydration, -9% to <-20%). , which is often found in coastal oceanic water, refused to drink seawater, but drank fresh water when dehydrated. In separate trials involving dehydration of and that were concurrently fed fish at regular intervals, snakes eventually refused to eat at TH of approximately -12% of original body mass, but resumed eating after they were allowed to drink fresh water and rehydrate. The drinking behaviors of corroborate previous data on the importance of fresh water for drinking, and they complement growing evidence that dietary water does not itself mitigate dehydration in snakes. These new data increase understanding of water relationships in the context of evolutionary transitions from land to sea, and they emphasize the importance of fresh water resources in the conservation of coastal and marine species of reptiles.
，这是一种海洋或半咸水两栖物种， 和 ，这两种都是淡水两栖物种。这三个物种都有相对较小且相似的脱水阈值（TH，大约为 -4%的体重损失），会引发口渴和饮用淡水。与几种hydrophiine 和 laticaudine 海蛇相比，这些物种的口渴敏感性更高，这些海蛇的 TH 更低（更大的脱水，-9%到<-20%）。 ，通常在沿海水域发现，拒绝饮用海水，但在脱水时会饮用淡水。在涉及同时定期喂食鱼类的 和 脱水的单独试验中，蛇最终在 TH 时拒绝进食，大约是初始体重的-12%，但在允许它们饮用淡水和重新水合后，它们会重新开始进食。 的饮水行为证实了先前关于淡水对饮水重要性的数据，并补充了越来越多的证据，即饮食中的水本身并不能减轻蛇的脱水。这些新数据增加了对从陆地到海洋的进化过渡背景下的水关系的理解，并强调了沿海和海洋爬行动物的淡水资源的重要性。
