Innovative attempts to raise tiger fugu in water originating from hot springs have been a great success in Nagano Prefecture.

The “tora” (tiger) puffer fish, bred in spring water normally used to fill the “onsen” at the foot of the Akaishi Mountains in the city of Iida, have recently grown large enough for shipment.

Hatched in the mountainous area known as Toyamagou in Iida’s Minamishinano district, there are high hopes this local specialty will change people’s notions of Nagano from an inland prefecture typically known for hot springs and ski resorts to a land of seafood delights.

Participants at a recent tasting party said the quality of Nagano’s onsen puffer fish rivals that of fugu from the sea.

Kagura no Yu, a hot springs hotel run by Minamishinano Promotion Corp., draws water rich in sodium and calcium chloride from deep in the earth. The company and the Hani Regional Industries Promotion Center noticed that the salinity of the hotel’s water was 0.73 percent, which is close to the salinity of the human body.

A company that breeds puffer fish in hot springs water from the town of Nakagawa, Tochigi Prefecture, provided the Nagano entities with 200 fugu fry last November.

The breeding process began in a circular water tank with a radius of 2 meters.

The first attempt wasn’t easy. In winter, breeders were busy keeping the water from getting too cold for the fish and meticulously removing their teeth to prevent them from eating each other.

The employees’ hard work finally paid off when a 400-gram tiger fugu more than doubled in size, reaching the threshold for shipment.

During a tasting party in the city last month, fugu sashimi, deep-fried fugu, fugu in rice porridge and “hirezake” (sake with grilled fugu fins), were served. Puffers bred in Mikawa Bay in Aichi Prefecture also were served. Participants said they couldn’t tell the difference.

“I am relieved that the breeding was successful enough that we could organize a tasting party. I hope to overcome any hurdles that may come with breeding the fish in summer and increase our farming knowledge. My goal is to ship the fish out for public consumption next year,” said Tokuzo Yamazaki, the owner of Kagura no Yu.

This section, appearing Saturdays, features topics and issues from the Chubu region covered by local daily Chunichi Shimbun. The original article was published May 9.