【Reading】ほんTuna

【English Name】Bluefin Tuna

Pacific bluefin tuna (scientific name: Thunnus orientalis), which circulates in the market under the name hon-maguro (true tuna), is a large saltwater fish belonging to the genus Thunnus of the family Scombridae. It inhabits the various waters of the Pacific from the tropics to the temperate zone, and grown individuals can reach 3 m in length and 400 kg in weight—the largest tuna species in the waters around Japan. With a thick, spindle-shaped body, the dorsal side wears a deep navy blue and the ventral side a silvery gray.

For sushi and sashimi it is served divided into akami (lean), chutoro (medium-fatty), and otoro (fatty), with large differences in fat content by part. The DHA per 100 g of akami is about 0.12 g, but for otoro it leaps up to about 3.2 g. Besides this, it appears on the table through a wide range of cooking methods such as negima nabe (hot pot with tuna and leek), various grilled dishes, and simmered preparations.

Fishing methods center on pole-and-line, longline, and purse seine, and in Japan pole-and-line is especially highly regarded. Amid concerns over declining resource volumes, the IUCN has designated it as Near Threatened, and catch-quota regulations are being strengthened in each country. In the field of aquaculture, Kindai University began research in 1970 and achieved full-cycle aquaculture through artificial hatching in 2002. Subsequently, multiple fisheries companies, beginning with Maruha Nichiro (2010), have also embarked on full-cycle aquaculture.

Note that, in light of its mercury content, the Ministry of Health, Labour and Welfare advises pregnant women to take a guideline of about 80 g once per week.