Native crayfish in Japan
Cambaroides japonicus
Called "NIHON-ZARIGANI"

The number of the peculiar crayfishes inhabiting Japan is one. It is a kind of a Cambaroides japonicus and is called the "NIHON-ZARIGANI". It is a very small size also in the crayfish in the world. Even if it becomes an adult, the length is about 10 cm in general. The gene analysis by a researcher shows that seemingly they are the ancestors of all the crayfishes which live in the Northern Hemisphere. They inhabit only the northern part of Japan. The main habitats are Hokkaido, Aomori Prefecture, Iwate Prefecture, Akita Prefecture, etc. They like the place where the water the origin part of the river always became clear is springing. They may inhabit the clear lake in the direction on a mountain. Even if it is a river and a lake, they need the environment where always clear water exists. If the surrounding woods are cut down or a certain construction is performed,From the habitat, a crayfish disappears in many cases. Even now, much they inhabit the place where environment is good. However, such a place decreases sharply every year. Many Japanese do not know that they are in a serious state. The government indicated them to the Red Data BookiVulnerable, VUjin 2000. We think that the habitat of them and them must be protected positively and it must go from now on also.