A scientist said Wednesday his team has found that an indigenous freshwater salmon species classified as extinct by the government around 70 years ago still exists in Lake Saiko, Yamanashi Prefecture.
Kyoto University professor Tetsuji Nakabo said he examined nine fish from the lake and found that their characteristics matched those of the "kunimasu," or black kokanee, salmon species.
If confirmed, it would be the first time a Japanese fish species classified as extinct has been found to be alive, the Environment Ministry said. The ministry said it will try to verify Nakabo's claim and possibly review its classification of the species.
The fish, a landlocked sockeye, had earlier been seen only in Lake Tazawa, Akita Prefecture, and was thought to have gone extinct after an inflow of acidic water into the lake starting around 1940.
However, Nakabo said there are records showing the salmon's eggs were taken to other lakes, including Lake Saiko and Lake Biwa in Shiga Prefecture, to develop their stocks about five years before the species was thought to have become extinct.
The species "likely propagated from the eggs from that time," Nakabo said.
The discovery came after Nakabo in February asked fish expert and TV celebrity Sakana-kun, who also serves as guest associate professor at Tokyo University of Marine Science and Technology, to draw a picture of the extinct fish.
Sakana-kun sent for samples of "himemasu" — another type of sockeye salmon close to kunimasu — from Lake Saiko and found some of the fish had features similar to kunimasu.
