Salmon, Pastel drawing by Chef Kaz Matsune
(Article originally posted on Quora.com)
If you ever wondered which part of a fish is used for Sashimi and Nigiri, here is an answer.
Please look at the pictures below.
If you look at the whole salmon, what is NOT painted in green, is suitable for Sashimi.
Tail flesh is too lean for Sashimi, as it gets the most exercise. Therefore, normally, it's used for rolls.
If you look at the fillet, what's circled in red is ideal for Sashimi, with "A" being the best (belly, AKA Salmon Toro), followed by B and the rest in alphabetical order.