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Vol. 52, 2013
Comparison of the osmoregulatory capabilities among three
amphibious sea snakes (Laticauda
spp.) in Taiwan
Yuan-Cheng
Cheng1, Ming-Chung Tu1,
Jyuan-Ru Tsai2, Hui-Chen
Lin2,3 and Li-Yih Lin1*
1Department
of Life Science, National Taiwan Normal University, Taipei 116, Taiwan
2Department of Life Science, Tunghai University,
Taichung 40704, Taiwan
3Center for Tropical Ecology and Biodiversity, Tunghai
University, Taichung 40704, Taiwan
Abstract
Background: The three species of
amphibious sea snakes (Laticauda
semifasciata, L. laticaudata,
and L. colubrina) in Taiwan
were described as having different habitat affinities from terrestrial
to marine. In this study, the osmoregulatory capabilities of three
species were compared to test if their capabilities were associated
with different habitat affinities.
Results: The sea snakes were transferred from a
terrestrial environment to freshwater (FW) or seawater (SW) for 1 week,
and then, Na+/K+-ATPase (NKA) activities of the salt
gland (sublingual glands) and kidneys, the water content of the
muscles, the body fluid osmolality, and Na+, Cl-, and K+ concentrations were measured. Results
showed that the body fluid osmolality, Na+ and Cl- levels, and muscle water content of most
marine species, L. semifasciata,
remained relatively constant, and the NKA activity of its salt gland
was approximately threefold higher than those of L. laticaudata and L. colubrina. In both L. semifasciata and L. laticaudata, NKA activities of
the salt glands were higher in SW than in FW; however, no significant
change was found in L. colubrina
(the most terrestrial species).
Conclusions: This study suggests
that the NKA activity of the sublingual gland is associated with salt
excretion, and the three species possess different osmoregulatory
strategies which are associated with their habitat affinities.
Key words: Sea snake; Salt gland;
Osmoregulation; Na+/K+-ATPase.
*Correspondence: E-mail: linly@ntnu.edu.tw
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