BABONIS, L. S. *; LILLYWHITE, H.B.; HATCH, K. ; TU, M. C.; University of Florida; University of Florida; Brigham Young University, Provo, UT; National Taiwan Normal University, Taipei: Drinking of Fresh Water by Sea Snakes

Recent field observations at Orchid Island, Taiwan, suggest that sea snakes are more abundant at sites having near-shore sources of fresh water (springs or estuaries), compared with strictly marine sites. We quantified the relative abundance of sea snakes by means of nocturnal surveys when snakes were active in shallow coastal pools. The mean number of snakes observed hourly was 22 � 19.0 at three marine sites with freshwater inflow, but only 1 � 1.7 at three strictly seawater sites. No snakes were found at a coastal spring that was entirely fresh water. In the laboratory, we dehydrated three individuals each of the amphibious sea snakes Laticauda laticaudata (146.9 � 1.9 g mean wet mass) and L. semifasciata (533.7 � 38.2 g). Snakes were held in mesh bags outside of water for a period of 5 days. In spite of greater mass, individuals of L. semifasciata lost a larger percentage of body mass during the dehydration period than did those of L. laticaudata (6.27 � 3.2 % vs. 5.63 � 1.9 %). The three dehydrated L. laticaudata drank fresh water in amounts of 2.3, 2.7 and 7.4 % of initial body mass, respectively, whereas none of the L. semifasciata drank fresh water. Previous studies have documented freshwater drinking in two other species of marine snake (Guinea, 1991; Lillywhite & Ellis, 1994). Our studies at Orchid Island are part of ongoing investigations that incorporate direct observations as well as stable isotope analyses to evaluate the generality of freshwater use in marine snakes.