Hynobius tsuensis Abé, 1922
Tsushima Sansho-uo, Tsushima Salamander
© 2004 Henk Wallays (1 of 13)
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Japan
Life History, Abundance, Activity, and Special Behaviors
Hynobius tsuensis belongs to the family Hynobiidae, which is one of only two salamander families exhibiting external fertilization of eggs. H. tsuensis breeds in running water, attaching its egg sacs to the undersides of rocks or other places in brooks. The egg sacs are banana-shaped and contain a small number of relatively large (ca. 3 mm) eggs. The total clutch contains 27-75 eggs, of which as many as 50% may be unfertilized. Some larvae metamorphose before autumn, but a large proportion of them overwinter as larvae. There is little information available on the natural history of H. tsuensis outside the breeding season. Larvae that leave the water before autumn do not disperse far from the stream of birth until the following year. From collection data it is surmised that adults return to the vicinity of the breeding sites in late autumn and early winter, where they overwinter in preparation for the next breeding season (Goris and Maeda 2004). 
Goris, R.C. and Maeda, N. (2004). Guide to the Amphibians and Reptiles of Japan. Krieger Publishing Company, Malabar, Florida.
Originally submitted by: Nichole Winters (first posted 2007-02-12)
Edited by: Kellie Whittaker (2007-06-14)
Species Account Citation: AmphibiaWeb 2007 Hynobius tsuensis: Tsushima Sansho-uo <https://amphibiaweb.org/species/3900> University of California, Berkeley, CA, USA. Accessed Mar 30, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 30 Mar 2023.
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