What kind of animal is the Japanese river otter? An explanation of its characteristics, ecology, and habitat


What kind of animal is the Japanese river otter? We will explain its characteristics, ecology, and habitat. Unfortunately, since it is already extinct, there is no footage of it, but we have compiled detailed information about what kind of animal it was in this article.

What is a Japanese River Otter? Basic Stats

The Japanese river otter is an otter that lived in Japan. Its English name is Japanese river otter, its scientific name is Lutra nippon, and its kanji is Nihonkawaotta. Its body length is 64.5-82.0cm, its tail length is 35-56cm, and its weight is 5-11kg. The list of information is as follows.

English(英名)Japanese river otter
scientific name(学名)Lutra nippon
Lutra lutra whiteleyi
classification(分類)Mammalia、Carnivora、 Mustelidae、Lutra


During the Meiji period, Japanese river otters were found on Rebun Island, and since then they have lived widely throughout Japan, from the mainland to the islands, including Hokkaido, Honshu, Shikoku, Kyushu, Iki Island, Tsushima, and the Goto Islands.

What are its characteristics? What kind of creature is it?

Japanese river otters have eyes and nostrils located high on their faces so that they can be alert and keep their eyes above the water. They have high-quality fur, which helps prevent them from losing body heat in the water. They often live alone in the middle and lower reaches of rivers, on sandy beaches, and on rocky shores, and are known for their wide range of movement, which can reach up to 10 km. They are nocturnal and often rest during the day.

What is their personality like?

Japanese river otters are solitary animals that are intelligent and curious, and will try anything. They are friendly creatures, which is why they are wiped out by humans.

What is their ecology like?

Japanese river otters live by eating fish, shrimp, crabs, and frogs. They mate in the water from spring to early summer, and after a two-month gestation period, they can give birth to one or more babies. The babies begin to leave the nest around 56 days after birth and become independent. Its lifespan is thought to be around 20 years.

Do they have any natural enemies?

The natural enemies of the Japanese river otter are humans. They are the cause of their extinction.

Why did the Japanese river otter become extinct?

Why did the Japanese river otter become extinct? It is also listed in Appendix I of the Washington Convention, and we will explain the reason for its extinction. This animal is now also designated as a special natural monument of Japan.

Overhunting for fur

The Japanese river otter’s fur was known to be of good quality. Because of its excellent heat retention, overhunting was rampant from the Meiji to Showa eras. Records show that 891 otters were caught per year in 1906, but by 1918, this number had dropped dramatically to 7 per year. They were overhunted for their fur all over the country, and the Japanese government panicked and banned hunting throughout Japan.

High economic growth period

Japan was rebuilt after its defeat in World War II, and at that time it was in a period of high economic growth. This was a tragedy for the Japanese river otter. They lost their habitat due to embankment construction, deterioration of water quality, and land development, and they were also poached, so they disappeared at the end of the Showa era. Sightings in the wild decreased. It became extinct before it could be protected.

Possibility of survival

Investigations showed that the last confirmed species was in Kochi Prefecture in 1979, and since then, no sightings have been reported, leading the Ministry of the Environment to define it as an extinct species. However, in February 2017, a video taken by the University of the Ryukyus on Tsushima captured a creature believed to be an otter, and in 2020, a group of Kochi city officials released videos and photos of an animal resembling a Japanese otter in Otsuki Town, Kochi Prefecture. The debate is heating up as to whether it may still be alive. Research by experts is continuing and advancing.


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