Photo by takaokun
Aji sushi can be made from Japanese Jack mackerel or Spanish mackerel or Saba. They are all members of the mackerel family. Aji is one of the tastiest sushi because of it's mild oily texture.
It is considered one of the healthiest fish type. Being a cold water fish, it is high in omega-3 fatty acids. Mackerel are close relatives of the tuna but considerably smaller and have vertical stripes on their back and a very forked tails.