Look at this tuna. There are small holes. This is called sashi, tuna's disease. We normally remove these part.
I can say 90% of tuna have this.
You can guess wild tuna swim in the ocean and just like human beings. They don't have doctor there. But they have to survive.
I sometimes see worms inside of body. It is already dead.
It is like thin string.
I think this is the reason American doctor say to pregnant lady not to eat raw fish. But another reason is mercury. Tuna is almost end of food chain and save mercury.
I think yellow fin tuna don't have much sashi.
Bug eye tuna have more than other tuna.
This tuna's price is lower than normal because of this.