Freshwater Use by Sea Snakes

海蛇使用淡水

• 批准号: 0926802
• 负责人: Harvey Lillywhite
• 金额: $ 47.5万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2013-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0926802&HistoricalAwards=false
• 关键词: Freshwater; Use; Sea; Snakes

Living in seawater is challenging to marine animals such as sea snakes, which evolved from terrestrial ancestors and are widely distributed throughout much of the world's tropical ocean waters. Sea snakes were previously thought to drink seawater and excrete the excess salts using salt glands. However, recent research by the PI has shown that three species of "sea kraits" (a type of sea snake) actually dehydrate in seawater and must drink freshwater in order to remain in water balance. Marine snakes must acquire freshwater by drinking from surface lenses that form on the sea during rainfall, or from freshwater springs or estuaries along coastlines. The objectives of this research are to test whether 'true sea snakes' also require fresh water for normal water balance. These are a second lineage containing the majority of sea snake species (50+). The investigators will measure rates of dehydration in sea water and in air; observe, describe and document the drinking behaviors of sea snakes; and correlate the distribution of sea snake abundance with the local availability of fresh water. The long-range goal is to correlate the known geographic distribution of sea snakes with historic and current patterns of rainfall in both time and space, using geospatial analysis. Understanding the water requirements of sea snakes will improve the understanding of the geographical distribution of these animals, which is likely to change due to altering patterns of precipitation related to climate change. These studies may also assist in the understanding of recent population declines and local extinctions of sea snakes, which are important top predators on coral reefs. Sea snakes might be significant harbingers of climate change and could be possible indicators of the health of coral reefs, which are in serious ecological crisis. The unexpected water requirements of sea snakes might also have important implications for understanding water balance in other important marine vertebrates such as sea turtles. This project will foster international collaborations and create opportunities for training and exchange of graduate students between the United States, Costa Rica, and Australia.

生活在海水中对海蛇等海洋动物来说是一种挑战，海蛇是从陆地祖先进化而来的，广泛分布于世界上大部分热带海洋水域。此前，海蛇被认为喝海水，并用盐腺排泄多余的盐分。然而，PI最近的研究表明，三种“海蛇”(一种海蛇)实际上在海水中脱水，必须喝淡水才能保持水平衡。海洋蛇必须从降雨期间在海上形成的表面透镜或海岸线上的淡水泉或河口获得淡水。这项研究的目的是测试“真正的海蛇”是否也需要淡水来维持正常的水分平衡。这是包含大多数海蛇物种(50+)的第二个谱系。研究人员将测量海水和空气中的脱水率；观察、描述和记录海蛇的饮水行为；并将海蛇数量的分布与当地淡水的可获得性联系起来。长期目标是利用地理空间分析，将已知的海蛇地理分布与历史和当前的降雨在时间和空间上的模式联系起来。了解海蛇对水的需求将提高对这些动物地理分布的了解，这种地理分布可能会因气候变化相关的降水模式变化而发生变化。这些研究还可能有助于理解最近海蛇的数量下降和局部灭绝的情况，海蛇是珊瑚礁上重要的顶级捕食者。海蛇可能是气候变化的重要先兆，也可能是处于严重生态危机的珊瑚礁健康状况的指标。海蛇意想不到的水分需求也可能对了解其他重要海洋脊椎动物(如海龟)的水平衡具有重要意义。该项目将促进国际合作，并为美国、哥斯达黎加和澳大利亚之间的研究生培训和交流创造机会。