| Common name | Koayu |
| Language | Japanese |
| Type | Vernacular |
| Official trade name | No |
| Rank | 3 - (Other common name) |
| Country | Japan |
| Locality | Lake Biwa and Lake Ikeda |
| Ref. | Masuda, H., K. Amaoka, C. Araga, T. Uyeno and T. Yoshino, 1984 |
| Life stage | juveniles and adults |
| Sex | females and males |
| Core | primary lexeme |
| 1st modifier | mod. for size |
| 2nd modifier | |
| Remarks | 'baby sweetfish' |