Meeting Abstract

P2.154  Thursday, Jan. 5  Can sea kraits detect freshwater resource? KIDERA, N.*; MORI, A.; TU, M.C.; National Taiwan Normal Univ.; Kyoto Univ.; National Taiwan Normal Univ. h089890@lab.u-ryukyu.ac.jp

Water is indispensable for any organisms. Most of marine animals possess physiological osmoregulation system to survive in the environment surrounded by higher salinity than their internal salinity. Sea snakes are also known to possess salt glands to excrete excess salts. Because of this, it has been thought that they are able to maintain water balance without consuming freshwater. Recent studies, however, demonstrated that amphibious sea kraits (Laticauda spp.) refuse seawater and require freshwater or highly dilute water to maintain water balance. Furthermore these studies revealed that the sea kraits are quite abundant at sites where freshwater are available. These facts suggest that the sea kraits require not only the physiological osmoregulation function but also the ability to detect freshwater. Using Laticauda species, we investigated their ability to discriminate water salinity. Dehydrated sea kraits were placed in Y-maze apparatus where freshwater and seawater were flowing out. Sea kraits selected more frequently the side connected to freshwater resource than the seawater side. Furthermore, the latency to reach freshwater resource was longer than that to reach seawater resource, implying that it takes times for the snakes to reach freshwater resource.