Lutra nippon Imaizumi and Yoshiyuki, 1989:178

Japanese otter, Japanese river otter



Taxonomy & Nomenclature

Synonym/s: Lutra lutra nippon Imaizumi and Yoshiyuki, 1989:178


Conservation Status


Last record: 1979

IUCN RedList status: Probably Extinct


The last confirmed sighting sighting of the Japanese Otter was on Shikoku Island in 1979, and the species/subspecies may be extinct (there is an ongoing taxonomic dispute as to whether the Japanese population represented a subspecies of the Eurasian Otter, or was a fully fledged species in its own right).

According to (Conroy et al. 1998) the last Japanese otter was found in 1986. However no source is stated and what they based their claim upon is unknown. Hence, the last record recognized by REPAD is 1979 pending further evidence for the 1986 record.

It was [url=]declared[/url] officially extinct by the Japanese government on the 28th of August, 2012. However, unofficial sightings continue to be reported on a regular basis (Torres, 2013).



Honshu, Kyushu and Shikoku, Japan


Biology & Ecology




Holotype: NSMT-M16201 (adult female)


Other specimens:









Original scientific description:

Imaizumi, Y. and Yoshiyuki, M. (1989). Taxonomic status of the Japanese otter (Carnivora, Mustelidae), with a description of a new species. Bulletin of the National Science Museum Tokyo Series A 15(3): 177-188.


Other references:

Abe, H., N. Ishii, Y. Kaneko, K. Maeda, S. Miura, and M. Yoneda. (1997). [A pictorial guide to the mammals of Japan.] Tokyo: Tokai University Press. Second ed. 195 pp. (in Japanese).

Akoi, A. (1995). Decline of the Japanese otter and its conservation in Kochi Prefecture. Proc. Korea-Japan Otter Symp. pp. 20-21.

Ando, M. (2008). The Japanese otter - lessons from its extinction. Tokyo: University of Tokyo Press. 233pp. [in Japanese]

Ando, M., Sasaki, H. (1996). Chronology of otter extinction in Japan, pp. 53-55. Proc. IUCN/SSC Asian Otter Specialist Group meeting, Thailand. Eds. Santiapillai, C., de Silva, P.K.

Ando, M., Yoshiyuki, M., Han, S. and Kim, H. (2007). Extinction of the Japanese Otter: -lessons from its extinction-. Paper presented in Xth International Otter Colloquium, Hwacheon, South Korea.

Conroy, Jim, Melisch, Roland and Chanin, Paul. (1998). The Distribution And Status Of The Eurasian Otter (Lutra Lutra) In Asia - A Preliminary Review. IUCN Otter Spec. Group Bull. 15(1): 15-30.

Endo, H., Ye, X. and Kogiku, H. (2000). Osteometrical Study of the Japanese Otter (Lutra nippon) from Ehime and Kochi Prefectures. Memoirs of the National Science Museum 33: 195-201. [Abstract]

Imaizumi, Y. (1949). The Natural History of Japanese Mammals. Yoyo Shobo, Tokyo, 348 pp.

Machida, Y. (1997). Tosa and the Japanese otter. In ‘Hello Japanese otter !’ (Kochi Shinbun Press, ed.), pp.34-62. The Kochi Shinbun, Kochi. [in Japanese].

Naito, Yuichi I. et al. (2015). Stable Carbon and Nitrogen Isotopic Composition of a Whisker and Fur from a Stuffed 19th Century Specimen of the Extinct Japanese River Otter Collected from Inland Honshu, Japan. Mammal Study 40(4): 265-269. [Abstract]

Ruiz-Olmo, J., Loy, A., Cianfrani, C., Yoxon, P., Yoxon, G., de Silva, P.K., Roos, A., Bisther, M., Hajkova, P. & Zemanova, B. (2008). Lutra lutra. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1. ( Downloaded on 15 October 2011.

Ryo Sakurai, Richard C. Stedman, Hiroshi Tsunoda, Hiroto Enari and Takuro Uehara. (2022). Comparison of perceptions regarding the reintroduction of river otters and oriental storks in Japan. Cogent Social Sciences 8(1): 2115656. doi:10.1080/23311886.2022.2115656

Sasaki, H. (1995). History of river otters in Japan. Proc. Korea-Japan Otter Symp. pp. 16-17.

Shinohara, Tatsuo. (1998). Friends of the otters Japan. Proceedings VIIth International Otter Colloquium, Trebon, Czech Republic. IUCN Otter Spec. Group Bull. 19A: 324-325.

Suzuki, T., Yuasa, H., and Machida, Y. (1996). Phylogenetic position of the Japanese river otter Lutra nippon inferred from the nucleotide sequence of 224 bp of the mitochondrial cytochrome b gene. Zoological Science 13: 621-626.

Torres, Ida. (2013). Numerous sightings of supposedly extinct Japanese otter reported. The Japan Daily Press, 20 February. Available online: [Accessed 20 March, 2013]

Waku, Daisuke and Sasaki, Takeshi. (2016). Evolutionary History of the Extinct Otter Lived in Japanese Islands. Adv. Tech. Biol. Med. 4: 4.

Waku, D., Segawa, T., Yonezawa, T., Akiyoshi, A., Ishige, T., Ueda, M. et al. (2016). Evaluating the Phylogenetic Status of the Extinct Japanese Otter on the Basis of Mitochondrial Genome Analysis. PLoS ONE 11(3): e0149341.

Yamamoto, K. and Ando, M. (2011). Trends in Otter-Related Newspaper Articles in Japan over 135 Years. Proceedings of XIth International Otter Colloquium, IUCN Otter Spec. Group Bull. 28B: 31 - 35.


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