There's a lot more to tuna than just canned fish. There are a number of varieties of tuna—15 species to be exact—but you are most likely to come across just these four: bluefin, yellowfin (also referred to as ahi), skipjack, and albacore.
The fish themselves range in size and color, with bluefin being the largest with dark red flesh, to skipjack, a lighter fleshed, smaller fish. Some varieties are best raw in sushi while others are ideal for canning. The varieties are very different from each other, so it is important you read your recipe carefully before substituting one kind of tuna for another.
This is a common variety with the lightest flesh and mildest flavor. It is frequently canned as white tuna and sold at a higher price than light chunk tuna. The Environmental Defense Fund reports the mercury level in albacore tuna is nearly three times as high as that of skipjack tuna. It is recommended that young children and pregnant and breastfeeding women watch their intake of albacore.
Bluefin tuna is often the variety of choice for fresh tuna connoisseurs. It has a bit more fat and flavor than the other varieties. When the bluefin is mature the flesh is dark red to almost purple. This variety is the largest, with the biggest fish recorded to have grown to about 1,600 pounds. Most of the bluefin harvest is exported to Japan and sold at a premium price for sashimi. Bluefin steaks can also be quickly seared and served sliced, still raw in the middle.
As you can surmise from its name, this fish likes to jump and skip over the surface of the ocean. This affordable variety of tuna is usually canned and is known as chunk light tuna. It generally has the strongest flavor and highest fat content and is also the smallest variety, seldom growing larger than 25 pounds. It is known as arctic bonito and aku—dried bonito is known as katsuobushi and is used in Japanese cuisine.
Yellowfin (Ahi) Tuna
Also known as ahi tuna, yellowfin is less expensive than bluefin but isn't far behind in quality. Yellowfin is also more common and easy to find in the grocery store or fish market. It is deep pink with flavor a bit stronger than albacore. Sashimi-grade raw ahi is used in poke bowls and sushi rolls. Searing and grilling is also a popular way to cook yellowfin tuna, and it can also be canned.
Cooking With Tuna
Everybody knows about the tried-and-true tuna salad, tuna melts, and tuna casserole. But there are so many other ways to cook tuna, including salad Nicoise (a French salad of tuna, olives, green beans, potatoes, and hard-boiled eggs with a delicious anchovy dressing), seared ahi tuna steaks, and spicy tuna sushi burgers. If using raw tuna steaks, it is important that you don't overcook—the fish tastes best when rare in the center (but of course, cook to your liking). If looking to make something out of the ordinary with canned tuna, consider deviled eggs with tuna, tuna risotto, or stuffed peppers with tuna.