It is hard to say which fish are best for your sushi because your country may not have the types I mention. One quick rule of thumb: larger fish like tuna are generally good to eat raw. Tuna blood is rich in iron and its amino acids break down slowly during the fermentation process, so tuna is ideal for eating raw. Small fish, especially those with shiny bluish backs, like sardines, tend to bruise easily, and even the Japanese will not eat them raw unless they are super fresh.
Keep fish at about 0°C because the protein fibers are shorter than in meat, making it easier for microorganisms to propagate. Carefully remove all of the scales and inner organs. Cleaning the fish properly is even more important than true freshness. When cutting and cleaning the fish, keep your knives, the knife handles, the cutting board and your hands as clean as possible.
Seafood suitable for sushi can be prepared in three ways:
·raw
·sprinkled with salt and/or allowed to sit in vinegar for a while