| Tokyo Bitterling | |
|---|---|
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Cypriniformes |
| Family: | Cyprinidae |
| Genus: | Tanakia |
| Species: | T. tanago |
| Binomial name | |
| Tanakia tanago (S. Tanaka (I), 1909) |
|
The Tokyo Bitterling (Tanakia tanago) is a temperate freshwater fish of the carp family. Taxonomically, it belongs to the Acheilognathinae genus of the Cyprinidae; there are around 1500 species of cyprinids worldwide, many in Asia.
In the wild, it is found only on the Kantō Plain of Japan, an area near to the capital city of Tokyo. It was formerly abundant in small streams, but its habitat has been overrun by people and pollution, and it was listed in the 1996 IUCN Red List as "Vulnerable", and there is a real risk that it could become extinct in the wild. It also suffers from competition from the closely related but more aggressive Rose Bitterling. Bitterlings lay their eggs in mussel shells, and the Tokyo Bitterling will only lay its eggs in one type of mussel shell, limiting its chances of successful breeding. To help protect it, it has been declared a "national monument" by the Japanese government which gives it special protection.
It was first described as Rhodeus tanago by Tanaka in 1990. The fish reaches a size of up to 5.0 centimetres (2.0 in).