Tuna Fish

In this guide, we describe the seven main species in the commercial tuna market. They vary dramatically in size, features, taste, and texture. But all provide significant nutrition and health benefits.

Tuna ranks among the top three most popular species year after year in North America. Its popularity is no surprise, as tuna can be found in all the world’s oceans and is enjoyed both fresh and canned.

Did you know there are 15 species of tuna? The seven listed below are considered main or major in the commercial tuna market. The remaining eight are still caught commercially and recreationally but not nearly in the volume as the main seven.

7 Main Tuna Species	8 Minor Tuna Species
Albacore	Black Skipjack
Bigeye	Blackfin
Atlantic Bluefin	Bullet
Pacific Bluefin	Frigate
Southern Bluefin	Kawakawa
Yellowfin	Longtail or Tongol
Skipjack	Little tunny
	Slender

Let’s see how they measure up:

Tuna Species	Maximum Weight	Maximum Length
Albacore Tuna	90 lbs	5 ft
Bigeye Tuna	400 lbs	8 ft
Atlantic Bluefin Tuna	2,000 lbs	10.5 ft
Pacific Bluefin Tuna	990 lbs	10 ft
Southern Bluefin Tuna	1,210 lbs	5 ft
Yellowfin Tuna	400 lb	7 ft
Skipjack Tuna	75 lbs	3.5 ft

These figures are estimates and vary based on factors such as age, location, and the individual fish. But it gives you an idea of the dramatic differences. Look how much bigger an Atlantic Bluefin is than a Skipjack!

7 MAIN SPECIES OF TUNA

Now we profile the seven major species of tuna in more detail.

ALBACORE

Distinguishing Features:

Elongate, fusiform body with a conical snout
Large eyes
Remarkably long pectoral fins
Deep blue dorsally and shades of silvery white ventrally
Unique diet preference for cephalopods (such as octopuses, squids, and cuttlefish)

Taste and Texture: Milder flavor than most tunas and meaty texture makes it suitable for various dishes, from salads to casseroles.

Habitat: Found in temperate and tropical waters worldwide, often inhabiting deep offshore areas.

Latin Name:Thunnus alalunga

BIGEYE

Distinguishing Features:

Large, deep-bodied, streamlined fish
Large head and eyes
Very long pectoral fins
13 or 14 dorsal spines
Unique physiology allowing them to forage in deeper, colder waters

Taste and Texture: Rich, sweet flavor with a clean, less “fishy” profile. The texture is firm and tender, ideal for searing or raw preparations.

Habitat: Prefers deeper, warmer waters in tropical and subtropical regions, often near islands or seamounts.

Latin Name: Thunnus obesus

ATLANTIC BLUEFIN

Distinguishing Features:

Distinguishing Features:
Dark blue coloring on the top and a gray or shimmering white coloring below
Gold shimmer to the entire body
Dark red meat
Tips of pectoral fins do not reach the front of the second dorsal fin

Taste and Texture: Mild, buttery, and savory flavor, with a subtle sweetness. The texture is firm and smooth, often enjoyed raw in sushi and sashimi.

Habitat: Occurs in the western and eastern Atlantic Ocean, migrating long distances and often found in cooler waters. The Mediterranean is a significant spawning ground for this species.

Latin Name: Thunnus thynnus

PACIFIC BLUEFIN

Distinguishing Features:

Black or dark blue dorsal sides with a grayish-green iridescence
Small eyes compared to other tuna species
Pectoral fin tips do not reach the front of the second dorsal fin

Taste and Texture: Pacific Bluefin has a distinct, succulent flavor with an oceanic essence. Its texture is firm and slightly chewy.

Habitat: As its name implies, it is found in the Pacific Ocean, ranging from the western Pacific to the eastern Pacific, and known for long-distance migrations.

Latin Name: Thunnus orientalis

SOUTHERN BLUEFIN

Distinguishing Features:

Found in open southern Hemisphere waters mainly between 30°S and 50°S
Maintains body core temperature up to 10°C above ambient temperature
Unique respiratory and circulatory adaptations for high metabolic demand

Taste and Texture: Southern Bluefin is buttery, smooth, and has a melt-in-your-mouth tender feel because it is marbled with fat.

Habitat: Inhabits the southern hemisphere’s temperate and cold waters, often found in the open ocean.

Latin Name: Thunnus maccoyii

YELLOWFIN

Distinguishing Features:

A yellow dorsal fin and yellow sides
Long second dorsal fin
Dark blue-black back and silver-white belly
Moderately large eyes
Yellow finlets on the tail

Taste and Texture: Yellowfin has a bolder flavor and softer texture than albacore. This makes it ideal where a richer tuna taste is desired, such as sandwiches or pasta dishes.

Habitat: Prefers tropical and subtropical waters worldwide, often near the surface or associated with floating objects. It can be found in the Mediterranean, mainly in the eastern basin and often associated with warm currents.

Latin Name: Thunnus albacares

SKIPJACK

Distinguishing Features:

Iridescent blue with black markings on the back
Bullet-shaped body
Tender meat, often used for canning
Smaller size compared to other tuna species

Taste and Texture: Skipjack tuna has a stronger, fishier flavor and a softer texture.

Habitat: Found in tropical and warm temperate waters worldwide, often in large schools near the surface.

Latin Name: Katsuwonus pelamis

NUTRITION AND HEALTH BENEFITS

Incorporating all types of tuna into your diet can provide a tasty and nutritious boost while potentially lowering the risk of various health conditions. Let’s delve into the nutritional value of tuna and its potential health benefits:

Nutritional Value

Vitamin B12: Tuna is an excellent source of vitamin B12, a crucial nutrient needed for DNA synthesis and the formation of new red blood cells. Adequate B12 intake helps prevent anemia and supports overall health.
Omega-3 Fatty Acids: Tuna is rich in omega-3s, which play a vital role in heart health. These fatty acids can help reduce inflammation, lower levels of harmful LDL cholesterol, and maintain healthy arteries. Regular consumption of omega-3s is associated with a reduced risk of cardiovascular diseases, including heart attacks.
Vitamin D: Just 3 ounces of canned tuna provide up to 50% of the recommended daily level of vitamin D. Vitamin D is essential for bone health, immune system function, and optimal growth in children.

Health Benefits

Heart Disease: The omega-3s in tuna help maintain a healthy balance between omega-6 and omega-3 fatty acids, reducing the risk of heart disease. By keeping arteries clear and supporting cardiovascular health, tuna consumption contributes to overall well-being. Tuna is also naturally low in sodium and low-sodium or sodium-free options are available for canned tuna.
Cancer Prevention: Tuna’s omega-3 fatty acids are believed to inhibit tumor cell growth and reduce inflammation. Chronic inflammation is associated with several types of cancer, making tuna a valuable addition to a cancer-preventive diet.
Weight Management: Tuna is a lean protein, filling and satisfying without excess calories. Adolescents who regularly consume lean fish like tuna have been shown to lose more weight than those who don’t.

Frequently Asked Questions

Is tuna fish good for your body?

Yes, tuna fish is good for your body due to its heart-healthy omega-3 fatty acids and rich nutrient content. According to the FDA, the mercury present in tuna fish is not a risk for most people. However, the FDA recommends that children ages 1-11 and women who are pregnant or breastfeeding limit their tuna intake to no more than one serving (4 ounces) per week.

Is tuna the healthiest fish?

When it comes to healthy fish options, tuna is a great choice. It contains beneficial nutrients such as omega-3s and is a lean protein, so it’s filling and satisfying without bringing excess calories.

Why is tuna fish so expensive?

Certain types of tuna, such as bluefin are expensive due to limited supply. But canned tuna is affordable because it primarily comes from smaller tuna varieties that grow fast and are abundant. Plus, the canning process preserves tuna, extends its shelf life, and makes it cost-effective for mass production.

Sources:

https://www.iss-foundation.org/tuna-stocks-and-management/tuna-fishing/tuna-species

https://ocean.si.edu/ocean-life/fish/big-tunas

https://www.fisheries.noaa.gov/find-species

https://www.webmd.com/diet/health-benefits-tuna

https://www.americanoceans.org/marine-life-species/