The kunimasu, a black-colored trout native to Lake Tazawa in Akita Prefecture, Japan, was declared extinct in 1940 after the lake was acidified by diverted river water powering a hydroelectric project. Its rediscovery in 2010 — in Lake Saiko at the base of Mount Fuji, where eggs had been transplanted in the 1930s — was announced by ichthyologist Tetsuji Nakabo and quickly became a significant moment in Japanese conservation biology. This coin was issued eight years after that rediscovery.
The kunimasu, a black-colored trout native to Lake Tazawa in Akita Prefecture, Japan, was declared extinct in 1940 after the lake was acidified by diverted river water powering a hydroelectric project. Its rediscovery in 2010 — in Lake Saiko at the base of Mount Fuji, where eggs had been transplanted in the 1930s — was announced by ichthyologist Tetsuji Nakabo and quickly became a significant moment in Japanese conservation biology. This coin was issued eight years after that rediscovery.