Aji, Saba and Iwashi: Oily Fish Sushi Guide

Aji, saba and iwashi are the "shiny fish" (hikarimono) of sushi — silver-skinned, oily and full of flavour. They are often cured or marinated, and a good test of a chef's skill.

At a glance. Aji (鯵): horse mackerel, mild and sweet, often raw with ginger and scallion. Saba (鯖): mackerel, rich and strong, usually salt-and-vinegar cured (shime-saba). Iwashi (鰯): sardine, soft and very oily, best very fresh.

Aji

Horse mackerel is the gentlest of the three — sweet, clean and lightly oily. It is often served raw with grated ginger and scallion to balance the richness.

Saba

Mackerel spoils quickly, so it is traditionally cured with salt and vinegar (shime-saba). The cure firms the flesh and tames its strong flavour. Seared mackerel is also popular — diners at Sushi Sadayama in Sheung Wan describe seared mackerel with shiso. See best sushi in Sheung Wan.

Iwashi

Sardine is soft, rich and oily, best in season when it is fattest. It must be very fresh.

Kohada

The fourth classic hikarimono is kohada (gizzard shad), salted and vinegared — the traditional test of an Edomae chef. See Edomae explained.

New to oily fish? Start with aji, then shime-saba. They are milder than people expect.

Health: oily fish are rich in omega-3. Smaller fish like sardines and mackerel are generally lower in mercury than large predators such as tuna and swordfish.

Curing doesn't kill parasites. Mackerel and other oily fish can carry Anisakis. Vinegar curing does not kill it; proper freezing or cooking does. Choose reputable restaurants.

Common questions

What is hikarimono?

"Shiny things" — silver-skinned fish such as aji, saba, iwashi and kohada.

Is saba raw?

Usually cured with salt and vinegar.

Where else can I look?

See our sushi fish guide.

Compiled by our editorial team from Japanese seafood and sushi references, chain and restaurant menus, and Hong Kong food safety guidance, retrieved September 2026. Seasons vary by region and year. General information only, not medical or dietary advice.