AmphibiaWeb - Hynobius tokyoensis


(Translations may not be accurate.)

Hynobius tokyoensis Tago, 1931
Tokyo Salamander
Subgenus: Hynobius
family: Hynobiidae
subfamily: Hynobiinae
genus: Hynobius

© 2021 Benjamin Monod-Broca (1 of 35)
Conservation Status (definitions)
IUCN Red List Status Account Vulnerable (VU)
National Status None
Regional Status Near Threatened at Kanto District on Honshu Island in Japan
Access Conservation Needs Assessment Report .



View distribution map in BerkeleyMapper.
View Bd and Bsal data (1 records).

A small species of Hynobius, often compared to other species H.lichenatus and H. nebulosus, but acknowledged as a separate distinct species. H. tokyoensis possesses 12 costal grooves. The vomerine teeth form a 'U'-shape. H. tokyoensis lays eggs in a pair of hard, banana-shaped egg saves. (Matsui & Nishikawa,2001)

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Japan


View distribution map in BerkeleyMapper.
View Bd and Bsal data (1 records).
Hynobius tokyoensis is mainly distributed in two completely isolated regions. (1) Fukushima Prefecture southwestwards through Tokyo to Kanagawa Prefecture out westwards through Tokyo to Kanagawa Prefecture of the Kanto District; and (Aichi Prefecture of the Chubu District of Honshu, the main island of Japan.) (Matsui & Nishikawa 2001) The discontinuous distribution pattern of the salamander is related to the distribution pattern of hills or small mountains that contain their specific habitat: areas kept moist by underground water that oozes out to the surface. (Sadao 2002)

Trends and Threats
Urban construction, water pollution, invasive species and habitat loss are some of the main threats affecting this species.

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Local pesticides, fertilizers, and pollutants
Predators (natural or introduced)

The karyotype of Hynobius tokyoensis is 2n = 56


Ihara, S. (2002). ''Site selection by Hynobius tokyoensis for breeding in a stream.'' Current Herpetology, 21(2), 87-94.

Kuro-o, M., Ikebe, C., Izumisawa, Y., Fujinuki, Y., Sasaki, K., Saso, K., Akaba, K., and Kohno, S. (2002). ''Cytogenetic studies of Hynobiidae (Urodela). XVIII. A ZZ/ZW sex-determining mechanism in a hynobiid salamander species, Hynobius tokyoensis Tago.'' Cytogenetic and Genome Research, 99(1-4), 194-199.

Matsui, M., and Nishikawa, K. (2001). ''Systematic status of Hynobius tokyoensis (Amphibia: Urodela) from Aichi Prefecture, Japan: a biochemical survey.'' Zoological Science (Tokyo) (Supplement), 18, 43.

Originally submitted by: Gary Tsai (first posted 2005-10-24)
Edited by: Tate Tunstall (2007-01-16)

Species Account Citation: AmphibiaWeb 2007 Hynobius tokyoensis: Tokyo Salamander <> University of California, Berkeley, CA, USA. Accessed Apr 18, 2024.

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Citation: AmphibiaWeb. 2024. <> University of California, Berkeley, CA, USA. Accessed 18 Apr 2024.

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