Abstract
Recent studies have shown that sea kraits (Laticauda spp.) – amphibious sea snakes – dehydrate without a source of fresh water, drink only fresh water or very dilute brackish water, and have a spatial distribution of abundance that correlates with freshwater sites in Taiwan. The spatial distribution correlates with sites where there is a source of fresh water in addition to local precipitation. Here we report six years of longitudinal data on the abundance of sea kraits related to precipitation at sites where these snakes are normally abundant in the coastal waters of Lanyu (Orchid Island), Taiwan. The number of observed sea kraits varies from year-to-year and correlates positively with previous 6-mo cumulative rainfall, which serves as an inverse index of drought. Grouped data for snake counts indicate that mean abundance in wet years is nearly 3-fold greater than in dry years, and this difference is significant. These data corroborate previous findings and suggest that freshwater dependence influences the abundance or activity of sea kraits on both spatial and temporal scales. The increasing evidence for freshwater dependence in these and other marine species have important implications for the possible impact of climate change on sea snake distributions.
Highlights
Water is essential to organisms, which have evolved numerous adaptations for maintaining adequate body water content
Studies of sea kraits at Lanyu (Orchid Island), Taiwan, demonstrate that the spatial distribution of abundance correlates with sites where there is a source of fresh water other than direct rainfall, or where fresh water is abundant [2]
In 2007 we observed that counts of sea kraits were consistently lower than in previous years, and these coincided with unusual drought on the island
Summary
Water is essential to organisms, which have evolved numerous adaptations for maintaining adequate body water content. It was long thought that sea snakes and other marine reptiles obtained water directly or indirectly from sea water, using extrarenal salt glands to eliminate excess salt. It is clear, that amphibious sea kraits (Laticauda spp.) dehydrate without a source of fresh water and require fresh water for water balance [1,2]. Studies of sea kraits at Lanyu (Orchid Island), Taiwan, demonstrate that the spatial distribution of abundance correlates with sites where there is a source of fresh water other than direct rainfall, or where fresh water is abundant [2]. We tested the hypothesis that sea krait abundance correlates positively with cumulative rainfall, which serves as an inverse index of drought
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
