“Extinct” Trout Found in Japanese Lake

The kunimasu trout, a fish believed extinct for the last 60-70 years, has been found in a lake near Mount Fuji. The species used to live in Lake Tazawa, which was polluted when river water was added for a hydroelectric power project. The river water was very acidic and killed the trout. Recently Kyoto University Professor Tetsuji Nakabo and TV personality Sakana-kun (Mr. Fish), found the trout again in Saiko Lake in the midst of a mess of rainbow trout.

DNA analysis confirmed the unrecognized trout as kunimasu. There were actually nine mixed in with the catch of rainbow trout. About 100,000 kunimasu eggs were brought to Saiko Lake from Lake Tazawa before the hydroelectric project construction fouled the waters of Tazawa. Because the eggs were brought there 75 years ago, it is likely the re-population efforts were simply forgotten and no follow-up was conducted or documented.

Oddly, Saiko Lake fishermen knew of the kunimasu being there, but they have called them “black trout.”

Lake Saiko – where the trout was re-discovered

lake sai

Sakana-kun said, “We should take this opportunity to think about the value of nature and living creatures, so as not to send any species to extinction.” (Source: Yomiuri.co.jp) Sometimes an animal believed extinct that is re-discovered is called a Lazarus species. Let’s hope the kunimasu is not perceived as exotic due to its unusual story and fished into extinction (again).

Image Credit: Kyoto University
Lake Image Credit: Amarpreet.singh.in

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Terry V.
Terry V.2 years ago


Terry V.
Terry V.2 years ago

makes a person wonder how many species have gone extinct that we never new about.............

Fred Hoekstra
Fred Hoekstra2 years ago

Thank you Jake, for Sharing this!

Teresa Wlosowicz
Teresa W.2 years ago

great news

Tim U.
Tim Upham3 years ago

Probably the best discovery since the coelacanth.

Elizabeth M.
Elizabeth M.3 years ago

Nature has a way of looking after itself!
This is exciting that the knunimasu trout thought to be extinct has been found.
Great News, thanks Jake.

Winn Adams
Winn Adams3 years ago


Marie W.
Marie W.3 years ago

Life keeps fighting.

John B.
John B.3 years ago

Great news. Thanls.

Danuta Watola
Danuta Watola3 years ago

Interesting, thank you.