Gifu Prefecture Ayu Hatchery

Gyobyou center ayu

Gifu Prefectural Ayu Hatchery


■ Objectives
Wild ayu resources change every year and they may not always fulfill the needs of fishermen. The Gifu Prefectural Ayu Hatchery was established in 1983 by joint investment of Gifu Prefecture and the Gifu Prefecture Federation of Fishermen’s Cooperatives in order to supplement shortages in wild ayu resources and to provide juvenile ayu generated from wild ayu for release into rivers.
The annual production of ayu in this hatchery has gradually increased since 1983. Currently, we produce more than 60,000kg of juvenile ayu in a year and fulfill an important role in providing stable fishery of ayu.
Annual Production of Ayu Juvenile in this Hatchery


■ Annual Aquaculture Plan for Ayu
[Fall-season]Collect eggs from wild matured ayu.
[Winter-season]Raise eggs to larvae.
[Spring-season]Release fry ayu into the river.
Annual Aquaculture Plan for Ayu


■Origin of Adult Ayu
It is preferable not to release groups that are genetically different from ayu originally live in the area in terms of continuous management of wild fish groups.
In order to keep genetic diversity specific to ayu in the Nagara River, we catch matured ayu mainly from the Nagara River and artificially collect eggs from them.
Origin of Adult Ayu


■Effective population size
The number of individuals that contribute to spawning and provide their genes to the next generation is referred to as the “effective population size.”
It is recommended to use at least 50 individual adult ayu in order to maintain genetic diversity.
Based on this standard, more than 1,500 individual males and more than 4,000 individual females are used for artificial fertilization every year in this hatchery.
Effective population size


■Number of Generations
When breeding fish continuously, much of the genetic diversity held by wild groups will be lost due to evolutionary reaction (genetic drift or natural selection).
In order to reduce this risk, continuous breeding of ayu is not implemented in principle in this hatchery.
Number of Generations .001

Tsukiji Outer Market Tour

Suzutoku Kaki

Enjoy Eating and walking


A couple from New York joined Tokyo Tsukiji Insider Tour. They were on their honeymoon. They arrived in Japan about 10 days before and visited some places such as Kyoto, Osaka, and Izu. The gentleman said he liked Izu the best of all for its rich nature and warm atmosphere. 
When we entered the intermediate wholesale market in Toyosu, they listened to what the guide explained, and sometimes asked the names of unfamiliar fish and how to cook them.
They were very interested in Japanese cuisine. In Tsukiji market, a variety of food sold at the street attracted them. “Today is the last day in Japan, so I want to try everything !”, said the gentleman with humor. They bought fried chicken, dumpling, shrimp-flavored fish cake, and also enjoyed sampling snacks such as wasabi-flavored peanuts, Japanese traditional bread with sweet bean paste, and Japanese omellete. 
When the tour ended, they smiled and said, “Yoi ichinichiwo ( Have a nice day ) !”.
Thank you very much for joining the tour.

About Fish Market

Iwate Key man You

A family from North Carolina in US joined Tokyo Sushi VIP tour.


We visited the intermediate wholesale market with our main chef. It was around 6 o’clock in the morning. The market was very lively right after the auction and the workers were very energetic, which attracted our guests very much. There were so many variety of fish. Among them, the father loved octopus and alfonsino, and the others preferred shrimp and crab. We visited some stores and got all of their requests. In addition, we got scallop from Hokkaido and a big block of tuna from Sakaiminato which was a very famous port for tuna’s catch.
Then, we headed to our kitchen studio where we had a sushi-making workshop. They made sushi with their favorite fish and seafood. The mother loved the sweetness of scallop and shrimp. The boys enjoyed salmon sushi. The father tasted several types of sake with sushi. Also, he was a big fan of whisky and would like to get some bottles. Our sushi master had deep knowledge about whiskey, so he recommended him a couple of good liquor shops in Tokyo.
After the tour, they would like to go back to their hotel by subway. About a week already passed since they had arrived in Japan, but it was the first time for them to use trains here. We explained the way to the hotel and how crowded the trains were during rush hour in Tokyo. They said, “Oh, good ! We like adventures !”
Thank you very much for joining our tour !

About Fish Workshop

Morioka Suzutoku Workshop

With Customers


Two brothers from United States joined our tour. We got a big whole salmon and a big block of tuna for Sushi-making workshop, which impressed the guests very much. It was rare opportunity even for Japanese to see a whole salmon, so our chef filleted it in front of the guests. They watched it with a lot of interest. Also, they had a chance to scale the salmon with knife under the help of our chef’s direction. They said, “it was difficult but so much fun to try !” Then, they learned how to fillet horse mackerel, which became one of their sushi toppings.
They made sushi a lot and enjoyed them with sake. There were four different taste of sake, ranging from dry to sweet. Their favorite was the sweetest. Aside from sushi, our chef made some dish such as tuna steak, grilled tuna skin, grilled fish ball, which made the guests so full and happy.
Thank you very much for joining us!