Frigate tuna nigiri

Frigate tuna (Hirasouda)

【Nigiri sushi: Akami】
“Soudagatsuo” is a collective term for the two species belonging to the same genus: Frigate tuna (Hirasouda) and Bullet tuna (Marusouda).

Hirasouda is considered to have a higher fat content and to be more flavorful than Marusouda. Both species lose their freshness quickly, and if not handled properly, they can cause histamine food poisoning. Marusouda, in particular, loses its freshness more quickly than Hirasouda and has more blood-rich flesh, so it is advisable to avoid eating it raw. Fresh Hirasouda, on the other hand, is delicious served as sashimi or tataki and is also used for nigiri sushi. Compared with bonito, it has a milder sourness and pairs well with vinegared rice, making it a milder and easier fish to eat. It is also delicious when marinated in soy sauce and grilled.

Marusouda, on the other hand, is particularly well suited for processed products, and both species are used to make Soudabushi and Namaribushi. In particular, Marusouda, which has a lower fat content, is an important raw material for Soudabushi. Soudabushi is rich in umami compounds such as inosinic acid and is characterized by a richer, more robust flavor than standard katsuobushi. For this reason, it is widely used as a broth base for noodle soups, sauces, and dishes such as kishimen.

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

(Revision date: September 7, 2026)