Horse mackerel nigiri

Horse mackerel (Aji)

【Nigiri sushi: Hikarimono】
With its beautifully shimmering silver skin, horse mackerel offers a firm, springy texture and a sweet, fatty flavor. Although fishing conditions vary by region, it is caught year-round and maintains a consistent quality throughout the year. However, small to medium-sized horse mackerel—the ideal size for sushi—reach their peak seasonality, particularly from the rainy season through summer.

In the past, it was common to marinate the fish in vinegar and serve it with the skin on. However, with advances in distribution and preservation technology, a steady supply of fresh fish is now available. As a result, the mainstream style today is to serve it either raw or quickly dipped in vinegar. As a garnish, a mixture of grated asatsuki (Japanese chives) and ginger juice is often used, adding a refreshing aroma and green color that enhances both the appearance and flavor of the nigiri sushi.

【Also known as】
Atlantic horse mackerel, Jack mackerel, Rough scad, Saurel

【What is Aji】
When people refer to “aji,” they are usually talking about ma-aji (Trachurus japonicus). It can grow to a total length of 40 cm. It is found in coastal waters around Japan, along the Korean Peninsula, and in the East China Sea and South China Sea. It is a migratory species that primarily inhabits midwater and bottom waters, from coastal areas to offshore waters. Juveniles live near the surface and feed on drifting seaweed. Its spawning grounds extend over a wide area south of the Tohoku region. Spawning occurs from winter to spring south of Kyushu, in spring in western Japan, and from spring to summer in eastern Japan.

Adult fish undertake seasonal migrations, moving north in spring and south in fall. Schools that migrate offshore in this way are called “kuro-aji” (black horse mackerel). They are characterized by their dark body color and slender shape. In contrast, schools of horse mackerel that do not migrate seasonally but remain in inner bays and around reefs are called “ki-aji” or “netsuki-aji” (resident horse mackerel). They have a yellowish body color and a somewhat stockier build. Ki-aji is generally considered to have better flavor and therefore commands a higher market price. Horse mackerel caught by handline in the waters of Hayasui-no-Seto, off Saganoseki in Oita Prefecture, are known as “Seki-aji” and are prized as a premium brand.

【Temperature of vinegared rice (shari) and sushi toppings】
36℃/20～23℃

【Trivia】
In recent years, the nonmigratory horse mackerel, with a yellow tinged body is popular. Seasonings decorated with a combination of chopped ginger and chives.

【Substitute fish】
Atlantic horse mackerel (Nishimaaji):Trachurus trachurus (Linnaeus, 1758)
Decapterus akaadsi Abe,1958
Japanese scad: Decapterus maruadsi (Temminck and Schlegel,1844)
Yellowtail horse mackerel or Southern Yellowtail Scad: Trachurus novaezelandiae Richardson, 1843

【Related contents】
What is Sujime?

What is Atarinegi?

List of Silver-skinned fish (Hikarimono)

(Previous revision date: May 15, 2025; Current revision date: November 12, 2026)