Chūtoro is the name for medium fatty tuna

Tuna

Tuna is a salt water fish from the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of . Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red coloration derives from myoglobin, an...

 when served in sushi

Sushi

is a Japanese food consisting of cooked vinegared rice combined with other ingredients . Neta and forms of sushi presentation vary, but the ingredient which all sushi have in common is shari...

 restaurant. A blue fin tuna yields Akami (red meat), chūtoro, and ōtoro (大とろ in Japanese, pink fatty tuna). Chūtoro is usually found near the skin on the back and belly. It combines the lighter but deep, slightly bitter flavor of an akami with the sweet tenderness of an ōtoro. It is quite expensive and usually served only on special occasions.