Department of Biology, University of Florida, Gainesville, Florida, United States of America.
Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America.
PLoS One. 2019 Feb 7;14(2):e0212099. doi: 10.1371/journal.pone.0212099. eCollection 2019.
Acquisition of fresh water (FW) is problematic for FW-dependent animals living in marine environments that are distant from sources of FW associated with land. Knowledge of how marine vertebrates respond to oceanic rainfall, and indeed the drinking responses of vertebrates generally following drought, is extremely scant. The Yellow-bellied Sea Snake (Hydrophis platurus) is the only pelagic species of squamate reptile and ranges across the Indo-Pacific oceans, having one of the largest geographic distributions of any vertebrate species. It requires FW and dehydrates at sea during periods of drought. Here we report drinking behaviors of sea snakes precisely at the transition from dry to wet season when rainfall first impacted the ocean following 6 months of seasonal drought. We show that the percentage of sea snakes that voluntarily drank FW in the laboratory when captured over eight successive days decreased from 80% to 13% before and after rainfall commenced, respectively. The percentage of snakes that drank immediately following capture exhibited a significant linear decline as the earliest rains of the wet season continued. Drinking by snakes indicates thirst related to dehydration, and thus thirsty snakes must have dehydrated during the previous six months of drought. Hence, the progressive decline in percentage of thirsty snakes indicates they were drinking from FW lenses associated with the first rainfall events of the wet season. These data reinforce the importance of accessing oceanic FW from precipitation, with implications for survival and distribution of pelagic populations that might be subjected to intensifying drought related to climate change.
获取淡水 (FW) 对于生活在远离与陆地相关 FW 源的海洋环境中的 FW 依赖动物来说是一个问题。关于海洋脊椎动物对海洋降雨的反应，以及事实上脊椎动物在干旱后对水的反应，人们知之甚少。黄腹海蛇 (Hydrophis platurus) 是唯一的远洋蜥蜴物种，分布于印度洋-太平洋海域，是任何脊椎动物物种中分布范围最广的物种之一。它需要 FW，并在干旱期间在海上脱水。在这里，我们报告了海蛇在旱季结束后首次受到降雨影响时，从旱季向雨季过渡期间的饮水行为。我们发现，在连续 8 天捕获海蛇时，自愿在实验室中饮用 FW 的海蛇比例从降雨开始前的 80%分别下降到降雨开始后的 13%。在雨季的最早降雨持续期间，立即饮水的蛇的比例呈显著线性下降。蛇的饮水表明与脱水有关的口渴，因此，在过去的六个月干旱中，口渴的蛇肯定已经脱水了。因此，口渴蛇的比例逐渐下降表明它们正在饮用与雨季第一次降雨事件相关的 FW 透镜中的水。这些数据强化了从降水获取海洋 FW 的重要性，这对可能受到与气候变化相关的日益严重的干旱影响的远洋种群的生存和分布具有重要意义。
