The President of the sushi restaurant chain Sushi Zanmai, Kiyoshi Kimura, cuts a blue fin tuna outside his main restaurant at the outer Tsukiji market in Tokyo January 5, 2015. The 180 kg blue fin tuna traded at a price of 4.5 million yen (37,500 USD) and was the most expensive fish at this year's New Year auction at the Tsukiji market, local media reported. (Photo by Thomas Peter/Reuters)

The President of the sushi restaurant chain Sushi Zanmai, Kiyoshi Kimura, removes the fin of a blue fin tuna outside his main restaurant at the outer Tsukiji market, in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

The President of the sushi restaurant chain Sushi Zanmai, Kiyoshi Kimura, removes the fin of a blue fin tuna outside his main restaurant at the outer Tsukiji market, in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

A man hauls frozen tuna after the New Year's auction at the Tsukiji fish market in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

Wholesalers attend the New Year's auction for frozen tuna at the Tsukiji fish market in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

An auctioneer gestures as wholesalers bid for frozen tuna during the New Year's auction at the Tsukiji fish market in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

An auctioneer (2nd L) gestures as wholesalers bid for frozen tuna during the New Year's auction at the Tsukiji fish market in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

Prospective buyers inspect the quality of fresh tuna before the first auction of the year at Tsukiji fish market in Tokyo, Monday, January 5, 2015. (Photo by Eugene Hoshiko/AP Photo)

A wholesaler checks the quality of frozen tuna displayed at the Tsukiji fish market before the New Year's auction in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

A wholesaler checks the quality of a frozen tuna displayed at the Tsukiji fish market before the New Year's auction in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

A wholesaler checks the quality of a frozen tuna displayed at the Tsukiji fish market before the New Year's auction in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

Wholesalers check the quality of frozen tuna displayed at the Tsukiji fish market before the New Year's auction in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

Fresh tuna are on display at the Tsukiji fish market before the New Year's auction in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

Wholesalers attend the New Year's auction of fresh tuna at the Tsukiji fish market in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

A wholesaler checks quality of a fresh tuna displayed at the Tsukiji fish market before the New Year's auction in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

Wholesalers check the quality of a fresh tuna displayed at the Tsukiji fish market before the New Year's auction in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

A chef of the sushi restaurant chain Sushi Zanmai holds the head of a blue fin tuna outside the chain's main restaurant at the outer Tsukiji market in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)

The President of the sushi restaurant chain Sushi Zanmai, Kiyoshi Kimura, cuts a blue fin tuna outside his main restaurant at the outer Tsukiji market in Tokyo January 5, 2015. (Photo by Thomas Peter/Reuters)