The left picture is called Oh-toro, fatty part of tuna.
Many people say that oh-toro is the best. No, it depends on how to eat.
It is sure that oh-toro has more fat than chu-toro which is medium toro.
But you can see so many lines. That is really chewy. Actually most of people don't know wild and farmed. Farmed oh-toro is not chewy. It is just soft and fat. But it does not have taste at all.
I always make special appetizer when I get wild oh-toro. That's toro abuli, seared toro.
By burn outside, meat get tender and easy to eat and get flavor.
Wild is wild, and farmed is farmed, never be the same.
By the way, people sometimes talk about fugu, blow fish. The blow fish come to USA does not have poison. Why? I think it is not wild, farm raised blow fish.
Blow fish get poison from food, a specific seaweed or kelp. Farm raised blow fish cannot eat same one and cannot have poison. And price is very low. Let's say, wild blow fish dish is around $300-$400 and farm raised blow fish dish is only $30-$50.
Same same, real is real, fake is fake.
If you want to eat real one, you need to go to Japan in winter time(between October to March only). Most of fugu restaurants are closed in off season.