Meeting Abstract

6.1  Jan. 4  Comparative immunolocalization of Na+/K+-ATPase and Na+/K+/2Cl- cotransporter in osmoregulatory tissues from marine and semi-marine snakes BABONIS, L.S.**; HYNDMAN, K.H.; LILLYWHITE, H.B.; Univ. of Florida, Gainesville babonis@ufl.edu

The sublingual salt gland is the primary site of salt excretion in sea snakes. Using histology and immunohistochemistry, we located two ion transporters, Na⁺/K⁺-ATPase (NKA) and Na⁺/K⁺/2Cl^– cotransporter (NKCC), in salt glands from three species of sea snake collected from Taiwan: Laticauda colubrina, L. laticaudata, and L. semifasciata. Both transporters were found in great abundance in the basolateral membranes of the tubular epithelia in all three species. These results are consistent with the localization of these transporters in other secretory tissues such as the gills of teleost fishes and the rectal salt glands of elasmobranchs. Unlike sea snakes, North American watersnakes in the genus Nerodia are not known to possess salt glands; however, at least two species in this genus inhabit marine and brackish water environments. Although reptiles are incapable of producing hyperosmotic urine, it is likely that some degree of osmotic stress can be counteracted by the kidneys. In addition, the ability to detect ephemeral sources of fresh water in marine environments could reduce the need for physiological osmoregulation. Therefore, we expect to find NKA and NKCC in the secretory tubules of watersnake kidneys and the chemosensory tissues of the oral epithelia. Understanding the relationships between the physiology and behavior of semi-marine snakes will lead to useful insights concerning the evolution of the fully marine species.