Longtail tuna nigiri

Longtail tuna (Koshinaga maguro)

【Nigiri sushi: Akami】
Longtail tuna (Koshinaga maguro, Thunnus tonggol) is a species of tuna that is extremely rare in the market and is seldom seen throughout the year. Due to its rarity, it is sometimes referred to as “Bake” in fish markets, and it is said that even among market professionals, few can clearly identify Koshinaga tuna. “Bake” is a market term used for a fish that closely resembles a well-known species but is actually a different one. Koshinaga tuna is given this name because it bears a striking resemblance to juvenile Pacific bluefin tuna, known as “meji maguro.”

Due to its limited distribution and low level of recognition, the market price of Koshinaga tuna is relatively low. In recent years, however, it has occasionally been landed in large quantities in areas such as Nagasaki, making caution against mislabeling advisable. Even so, it is rarely seen at the Toyosu Market.

Its flesh is slightly paler red than that of Pacific bluefin tuna, and its flavor is often compared to that of juvenile bluefin tuna. While it is not as fatty as bluefin tuna, it has a distinctive, clean finish that sets it apart from yellowfin tuna. Although it is sometimes served as sushi in Nagasaki, Shimane, and Yamaguchi prefectures, it is rarely featured intentionally at sushi restaurants in Tokyo. Instead, it is more commonly served as fresh sashimi at izakaya and similar establishments. It is by no means an unpalatable fish, but it is not a sushi topping worth seeking out specifically. However, if you happen to encounter it as a rare regional specialty, it is certainly worth trying.

【Related contents】
List of Red flesh fish (Akami)

(Written June 16, 2026)