What are the differences between ahi tuna and yellowfin, and which one is considered to be of higher quality for sushi?

Ahi tuna and yellowfin tuna are different species of tuna. Yellowfin tuna is generally considered to be of higher quality for sushi due to its mild flavor and firm texture. Ahi tuna, also known as bigeye tuna, has a richer flavor and is often used in cooked dishes rather than raw sushi.