15 Types of Tuna: Complete Species Guide 2026

Did you know there are actually 15 different types of tuna swimming in our oceans, not just the handful most people recognize at the seafood counter? From the colossal Atlantic Bluefin that can tip the scales past a ton to the diminutive Bullet Tuna barely larger than a dinner plate, the tuna family showcases extraordinary diversity that few realize exists.

Whether you're an angler planning your next offshore trip, a home cook selecting the best can for your salad, or a sushi enthusiast wanting to understand the difference between akami and otoro, this comprehensive guide has you covered. In 2026, understanding these distinctions matters more than ever as conservation concerns and culinary trends shape how we interact with these remarkable fish.

Over the next several thousand words, we'll explore every tuna species in detail, complete with IGFA world records, mercury level data, fishing techniques, and everything else you need to become a true tuna expert. Let's dive into the fascinating world of Thunnini.

What Are the 15 Types of Tuna?

The complete list of tuna species breaks down into two distinct categories: the seven main commercial species that dominate global markets, and eight lesser-known minor species that fill important ecological and regional economic roles. Understanding this division helps clarify why some tunas cost $3 per can while others fetch $3 million at auction.

7 Main Commercial Species	8 Minor Species
Skipjack (Katsuwonus pelamis)	Black Skipjack (Euthynnus lineatus)
Albacore (Thunnus alalunga)	Blackfin Tuna (Thunnus atlanticus)
Yellowfin (Thunnus albacares)	Bullet Tuna (Auxis rochei)
Bigeye (Thunnus obesus)	Frigate Tuna (Auxis thazard)
Atlantic Bluefin (Thunnus thynnus)	Kawakawa (Euthynnus affinis)
Pacific Bluefin (Thunnus orientalis)	Longtail/Tongol (Thunnus tonggol)
Southern Bluefin (Thunnus maccoyii)	Little Tunny (Euthynnus alletteratus)
	Slender Tuna (Allothunnus fallai)

The seven main commercial species account for over 5.2 million tons of global catch annually, with Skipjack and Yellowfin representing a staggering 87% of that volume. These are the species you'll encounter at restaurants, fish markets, and grocery stores worldwide. The eight minor species, while less commercially valuable, play crucial roles in local fisheries and marine food webs across tropical and temperate waters.

Quick Reference Guide

Here's a rapid-fire summary of what makes each species unique:

Commercial Species Quick Facts:

• Skipjack: Most common canned tuna, strong flavor, lowest mercury (0.126 ppm), sustainable choice
• Albacore: "White tuna" in cans, mild flavor, moderate mercury (0.350 ppm), excellent for grilling
• Yellowfin: Versatile "ahi" tuna, great for steaks and sushi, moderate mercury (0.354 ppm)
• Bigeye: Premium sushi grade, high fat content, vulnerable status, highest mercury (0.689 ppm)
• Atlantic Bluefin: Largest and most expensive, endangered but recovering, prized for otoro
• Pacific Bluefin: Trans-Pacific migrator, critically endangered, culturally significant in Japan
• Southern Bluefin: Cold-water specialist, extensively farmed in Australia, rich sashimi quality

Minor Species Quick Facts:

• Black Skipjack: Eastern Pacific only, strong fighter, bloody meat
• Blackfin: Smallest true tuna, Atlantic species, excellent sportfish
• Bullet: Tiny speed demon at just 4 pounds, used for bait
• Frigate: Tropical worldwide, regional food source
• Kawakawa: Indo-Pacific coastal, strong flavor, popular in curries
• Longtail/Tongol: Enters rivers, Southeast Asian favorite, marketed as "Northern Bluefin"
• Little Tunny: "False albacore," great light-tackle sportfish, bloody meat
• Slender: Antarctic mystery fish, rarely seen by humans

Understanding Tuna Classification: True Tunas vs Minor Species

The Thunnini Tribe: Scientific Classification

All 15 types of tuna fish belong to the Thunnini tribe within the Scombridae (mackerel) family. This tribe represents one of the most economically significant fish groups on the planet, supporting multi-billion dollar industries across fishing, processing, and cuisine. The Thunnini classification helps scientists understand evolutionary relationships and the unique physiological adaptations that make these fish so successful.

The defining characteristics of Thunnini include their torpedo-shaped fusiform bodies, two distinct dorsal fins separated by a small gap, and a remarkable physiological trait called regional endothermy. Unlike most fish that simply match surrounding water temperature, tunas can maintain body temperatures significantly above ambient levels. This warm-blooded capability allows them to hunt efficiently across vast temperature ranges, from tropical shallows to deep, cold waters.

Genus Thunnus: The 8 True Tunas

The types of true tunas belong exclusively to genus Thunnus, containing eight species organized into two subgenera. The bluefin group (subgenus Thunnus) includes five species: Atlantic Bluefin, Pacific Bluefin, Southern Bluefin, Albacore, and Bigeye. These share the most sophisticated thermoregulation systems and generally reach the largest sizes. The yellowfin group (subgenus Neothunnus) contains three species: Yellowfin, Blackfin, and Longtail.

True tunas share several anatomical signatures: a robust fusiform body tapering to a narrow caudal peduncle with prominent keels, a series of 7-10 finlets behind the dorsal and anal fins, and specialized vascular networks called rete mirabile that conserve metabolic heat. These adaptations support their high-performance lifestyle as apex predators in pelagic ecosystems.

What Makes a Tuna "True" vs "Minor"?

The distinction extends beyond scientific taxonomy into practical characteristics. True tunas generally achieve larger maximum sizes, possess more advanced thermoregulation systems, and command higher market values. They undertake longer migrations and demonstrate more complex behavioral patterns than their minor counterparts.

Minor tunas, belonging to genera like Auxis, Euthynnus, and Katsuwonus, typically remain smaller throughout their lives. While Skipjack (genus Katsuwonus) dominates global tuna landings despite technically being a minor tuna, it lacks certain anatomical refinements of true tunas. These species often form enormous surface schools and serve as crucial prey for larger predators, filling vital ecological niches even when they don't command premium prices.

Tuna Size Chart: From Smallest to Largest

The size variation among tuna species spans nearly three orders of magnitude, creating one of the most dramatic size ranges within any fish tribe. This comprehensive tuna size chart presents all 15 species ranked by maximum recorded weight:

Species	Maximum Weight	Maximum Length	Average Weight	IGFA World Record
Bullet Tuna	4 lbs	1.6 ft	2 lbs	7 lbs 12 oz
Frigate Tuna	10 lbs	2.5 ft	5 lbs	11 lbs 11 oz
Little Tunny	35 lbs	4 ft	20 lbs	36 lbs 1 oz
Blackfin Tuna	45 lbs	3.5 ft	20 lbs	45 lbs 4 oz
Kawakawa	50 lbs	3.3 ft	25 lbs	40 lbs 5 oz
Black Skipjack	60 lbs	3 ft	30 lbs	26 lbs 8 oz
Skipjack	75 lbs	3.5 ft	40 lbs	76 lbs
Slender Tuna	80 lbs	3.2 ft	40 lbs	No official record
Albacore	90 lbs	5 ft	50 lbs	88 lbs 2 oz
Longtail/Tongol	130 lbs	4.5 ft	65 lbs	79 lbs 3 oz
Yellowfin	400 lbs	7 ft	150 lbs	427 lbs
Bigeye	400 lbs	8 ft	180 lbs	435 lbs
Pacific Bluefin	990 lbs	10 ft	300 lbs	804 lbs
Southern Bluefin	1,210 lbs	8 ft	350 lbs	348 lbs
Atlantic Bluefin	2,000 lbs	15 ft	550 lbs	1,496 lbs

Record-Breaking Tuna Sizes

The largest tuna ever caught was an Atlantic Bluefin weighing 1,496 pounds, landed off Nova Scotia in 1979 by angler Ken Fraser. This behemoth measured 107 inches in length with an 80-inch girth, representing the pinnacle of sport fishing achievement. To visualize the scale: you would need approximately 37 Bullet Tuna or 20 Skipjack to equal this single fish's weight.

Other notable IGFA records include a 612-pound Pacific Bluefin caught off California in 2023, a 435-pound Bigeye from Peru, and a 427-pound Yellowfin from Mexico. These giants can live 40-50 years for Bluefin species, compared to smaller varieties like Skipjack that typically survive just 8-12 years. The relationship between size and longevity directly impacts mercury accumulation, making size an important factor when evaluating seafood safety.

The 7 Main Commercial Tuna Species

1. Skipjack Tuna (Katsuwonus pelamis)

Skipjack tuna dominates global tuna landings, accounting for over 60% of all commercial catch. These energetic fish display distinctive dark horizontal stripes on their silver bellies, earning them the nickname "striped tuna" or "oceanic bonito" in some markets. Their streamlined, torpedo-shaped bodies achieve speeds exceeding 30 mph while hunting in tropical and warm temperate waters worldwide.

Found in all major oceans between 50°N and 40°S, Skipjack form massive surface schools often numbering in the thousands. They frequently associate with dolphins, sharks, floating debris, and thermoclines where prey concentrates. This schooling behavior makes them ideal targets for purse seine fishing, the primary commercial method, though pole-and-line fishing offers a more sustainable alternative with minimal bycatch.

From a culinary perspective, Skipjack provides the most common type of tuna in canned products, marketed as "chunk light" tuna. Its darker, softer meat delivers a stronger, more pronounced fish flavor compared to other species. While not typically served as sushi or steaks due to its softer texture, Skipjack excels in prepared dishes like tuna salad, casseroles, and sandwiches where bold flavors shine through other ingredients.

The IGFA all-tackle world record for Skipjack stands at 76 pounds, caught in the Maldives in 1996. Most commercial catches range 4-15 pounds, making them perfect for canning operations. From a sustainability standpoint, Skipjack represents the most responsible tuna choice due to rapid growth (reaching sexual maturity at one year), high fecundity, and healthy global populations.

2. Albacore Tuna (Thunnus alalunga)

Albacore tuna, marketed as "white tuna" or "chicken of the sea" in cans, stands out immediately by their extraordinarily long pectoral fins extending well beyond the second dorsal fin. These elegant fish display metallic blue backs fading to silver-white bellies, with the characteristic long fins making identification straightforward even at a distance.

Unlike many tunas that prefer tropical waters, Albacore favor temperate seas between 59-68°F and rarely venture close to shore. They inhabit all major oceans but prefer deeper offshore waters, following distinct migration routes across ocean basins. Their diet focuses heavily on cephalopods, particularly squid, along with small schooling fish like anchovies and sardines. Trolling with squid lures proves particularly effective for catching Albacore.

Commercially, Albacore represents about 20% of the U.S. canned tuna market, prized for its mild flavor and white meat that appeals to consumers seeking less "fishy" alternatives. The firm texture holds up beautifully to grilling, making Albacore steaks popular in restaurants. However, mercury concentrations run approximately three times higher than Skipjack (0.350 ppm vs 0.126 ppm), leading health organizations to recommend limiting consumption, particularly for vulnerable populations.

The IGFA world record Albacore weighed 88 pounds 2 ounces, caught in the Canary Islands in 1977. Pacific Albacore fisheries off California, Oregon, and Washington support important recreational and commercial operations, with trolled lures and live bait producing the best results. Current stocks remain relatively stable, though climate change impacts on their preferred temperature ranges pose ongoing management challenges.

3. Yellowfin Tuna (Thunnus albacares)

Yellowfin tuna, called "ahi" in Hawaiian (a term also applied to Bigeye), ranks among the most recognizable tuna species thanks to their brilliant yellow second dorsal and anal fins. These powerful swimmers hold the verified speed record for tuna at 47 mph, making them formidable predators and exhilarating sportfish across tropical and subtropical waters worldwide.

Adult Yellowfin develop distinctive sickle-shaped fins that grow disproportionately with age, creating a visual signature impossible to confuse with other species. In the Eastern Pacific, they famously associate with dolphins, a behavior that historically contributed to significant dolphin bycatch before modern mitigation practices. They also congregate around floating objects, seamounts, and temperature breaks where prey concentrates.

Culinarily, Yellowfin offers exceptional versatility. Its pale pink to deep red meat delivers a mild, slightly nutty taste that works equally well raw in sushi and poke or cooked as grilled steaks. The firm texture and moderate fat content prevent drying out during cooking, forgiving less experienced chefs while satisfying discerning palates. Mercury levels (0.354 ppm) fall between Skipjack and Albacore, making moderate consumption safe for most adults.

The IGFA world record Yellowfin weighed 427 pounds, caught in Mexico in 2012. While most commercial catches range 30-80 pounds, exceptional specimens exceed 300 pounds. Some Indian Ocean stocks show signs of overfishing, making method of catch important for sustainability-conscious consumers. Pole-and-line or troll-caught Yellowfin represents the most responsible choice.

4. Bigeye Tuna (Thunnus obesus)

Bigeye tuna earn their name from disproportionately large eyes, an evolutionary adaptation for hunting in deep, dark waters where sunlight barely penetrates. These remarkable fish undertake daily vertical migrations, diving to depths exceeding 1,600 feet during daylight hours before rising to shallower waters at night to feed. This behavior pattern distinguishes them from surface-dwelling species like Skipjack and most Yellowfin populations.

Their deep-diving ability stems from specialized physiology allowing tolerance of cold temperatures and low oxygen levels. Bigeye maintain body temperatures even more efficiently than other tunas, preserving warmth in waters as cold as 40°F. Bigeye characteristics include exceptional marbling and fat content that rivals Bluefin species, making them prized for premium sushi applications.

In sushi restaurants, Bigeye often substitutes for more expensive Bluefin, offering similar rich flavor and buttery texture at lower price points. The deep red meat contains high fat content, creating excellent "toro" cuts when taken from the belly. However, their deep-diving habits lead to the highest mercury accumulation among commonly consumed tunas at 0.689 ppm, prompting FDA warnings for pregnant women and young children.

The IGFA world record Bigeye weighed 435 pounds, caught in Peru in 1957. Unfortunately, global populations have declined significantly, with the IUCN listing them as "vulnerable." Their tendency to aggregate around Fish Aggregating Devices (FADs) makes them susceptible to overfishing. Consumers seeking sustainable options should choose hook-and-line caught Bigeye or consider alternatives like Yellowfin for similar culinary applications.

5. Atlantic Bluefin Tuna (Thunnus thynnus)

Atlantic Bluefin tuna reign as the undisputed giants of the tuna world, capable of exceeding 15 feet in length and 2,000 pounds in weight. These magnificent predators display metallic blue backs, silver sides, and can live half a century. Their football-shaped bodies and powerful lunate tails generate bursts up to 43 mph, enabling trans-Atlantic migrations between feeding and spawning grounds.

Found throughout the Atlantic Ocean and Mediterranean Sea, Atlantic Bluefin undertake one of the ocean's most impressive migrations, crossing between North American and European waters seasonally. They tolerate water temperatures from just above freezing to tropical warmth, thanks to sophisticated thermoregulation systems that maintain core temperatures up to 20°C above surrounding water. Bluefin conservation has become a major focus of international fisheries management.

Culinarily, Atlantic Bluefin represents the absolute pinnacle of sushi and sashimi. The fatty belly meat (otoro) commands astronomical prices, with individual fish selling for millions at Japanese auction. Different cuts from the same fish vary dramatically: lean akami from the back, medium-fatty chutoro from the upper belly, and ultra-rich otoro from the lower belly. The meat's complex umami flavor and buttery melt-in-your-mouth texture make it irreplaceable in high-end cuisine.

The IGFA world record Atlantic Bluefin weighed 1,496 pounds, caught off Nova Scotia in 1979. This record still stands today, representing the ultimate achievement in sport fishing. Decades of overfishing pushed Atlantic Bluefin to the brink, but strict management through ICCAT (International Commission for the Conservation of Atlantic Tunas) has enabled modest recovery. They remain vulnerable, however, and consumers should seek certified sustainable sources or choose alternative species.

6. Pacific Bluefin Tuna (Thunnus orientalis)

Pacific Bluefin tuna share many characteristics with their Atlantic cousins but follow different life patterns shaped by the vast Pacific Ocean. These powerful fish spawn exclusively in the Western Pacific near Japan and the Philippines, with some juveniles embarking on an incredible trans-Pacific migration to feeding grounds off California and Mexico. This 5,000-mile journey ranks among the longest migrations in the marine world.

Physically smaller than Atlantic Bluefin but still impressive, Pacific Bluefin can reach 10 feet and nearly 1,000 pounds. They display proportionally smaller eyes than other Bluefin species and distinctive black-blue coloring on their dorsal side. Like other true tunas, they maintain body temperatures significantly above ambient water, enabling efficient hunting across diverse thermal environments from the Sea of Japan to Baja California.

In Japanese cuisine, Pacific Bluefin holds special cultural significance, particularly for New Year celebrations when the first tuna auction generates worldwide attention. Record prices reflect prestige and tradition rather than pure market economics. The annual first tuna auction at Tokyo's Toyosu Market routinely produces six-figure sales, with the record reaching $3.1 million for a 612-pound specimen in 2019. The history of tuna endangerment prominently features Pacific Bluefin.

The IGFA world record Pacific Bluefin weighed 804 pounds, caught off New Zealand in 1997. Unfortunately, Pacific Bluefin face severe conservation challenges, with populations at historically low levels estimated at less than 3% of unfished biomass. Unlike fast-reproducing species, Bluefin take 5-7 years to reach maturity, making population recovery slow even with reduced fishing pressure. International cooperation between Pacific nations has implemented catch reductions, but recovery remains a long-term challenge.

7. Southern Bluefin Tuna (Thunnus maccoyii)

Southern Bluefin tuna inhabit the cold waters of the Southern Hemisphere, ranging between 30°S and 50°S latitude across the Indian, Pacific, and Atlantic sectors of the Southern Ocean. These remarkable fish maintain body temperatures up to 10°C above surrounding water, allowing them to thrive in conditions that would challenge other tuna species. Their deep blue-black backs and silver bellies provide camouflage in the open ocean environment.

Young Southern Bluefin spend their first years in the relatively warmer waters off Australia before venturing into the frigid Southern Ocean as adults. They undertake extensive migrations following prey and optimal water temperatures, feeding primarily on small fish, squid, and krill found in these productive polar waters. Their cold-water adaptation makes them unique among major commercial tunas.

Australia pioneered Southern Bluefin farming, capturing young wild tuna and fattening them in sea pens off Port Lincoln. This practice, while controversial among conservationists, allows fish to reach premium market size while theoretically reducing pressure on wild stocks. The farmed fish develop exceptional marbling during their 6-8 month pen residence, producing sashimi that rivals the finest wild Bluefin. The meat's deep red color and high fat content command premium prices in Japanese markets.

The IGFA world record Southern Bluefin weighed 348 pounds, caught in Australia in 2009. Like other Bluefin species, Southern Bluefin suffered catastrophic overfishing in the late 20th century, with populations declining over 90% from historical levels. The Commission for the Conservation of Southern Bluefin Tuna now manages the fishery through strict quotas and monitoring. Recent stock assessments show modest recovery, but the species remains endangered. Choosing certified sustainable seafood helps support recovery efforts.

The 8 Minor Tuna Species Most People Don't Know

1. Black Skipjack (Euthynnus lineatus)

Black Skipjack, despite its common name, displays beautiful blue-black coloring with distinctive wavy or broken lines along the back. Found exclusively in the Eastern Pacific from Southern California to Peru, these fish prefer coastal waters near the continental shelf. They're most abundant in tropical waters near Ecuador and the Galapagos Islands, where nutrient upwelling creates rich feeding grounds.

Reaching maximum sizes around 60 pounds, Black Skipjack form large schools that frequently mix with other small tunas and bonitos. They're voracious surface predators, feeding on small fish, squid, and crustaceans. Sport fishermen prize them for their powerful fighting ability, though their dark, bloody meat makes them less desirable for consumption than other tunas. The IGFA record stands at 26 pounds 8 ounces, caught in Mexico.

2. Blackfin Tuna (Thunnus atlanticus)

Blackfin tuna, the smallest true member of genus Thunnus, inhabits the warm waters of the Western Atlantic from Massachusetts to Brazil. Their distinctive black fins against a steel-blue body make identification straightforward. These compact fish rarely exceed 45 pounds and prefer temperatures above 68°F, staying within the continental shelf waters where food is abundant.

Despite their modest size, Blackfin are prized by sport fishermen for their incredible fighting ability pound-for-pound. They often school with Skipjack and feed aggressively on small fish and squid. While not commercially important due to their size, Blackfin make excellent table fare when fresh, with lighter meat than most tunas. The IGFA world record weighed 45 pounds 4 ounces, caught in Florida in 1996.

3. Bullet Tuna (Auxis rochei)

Bullet tuna earn their name from their torpedo-shaped bodies and explosive acceleration capabilities. These tiny tunas, reaching only 4 pounds maximum, form massive schools in tropical and subtropical waters worldwide. Their blue-black backs feature distinctive wavy lines similar to their close relatives, the Frigate tuna, but their smaller maximum size distinguishes the two species.

In the Mediterranean and parts of Asia, Bullet tuna support small-scale artisanal fisheries. Their meat, while strongly flavored, appears in regional dishes when fresh. Ecologically, they serve as important prey for larger predators including bigger tunas, billfish, and marine mammals. Commercial operations frequently use them as bait for longline fishing targeting larger species. The IGFA record stands at 7 pounds 12 ounces.

4. Frigate Tuna (Auxis thazard)

Frigate tuna closely resemble Bullet tuna but grow slightly larger, reaching 10 pounds. They inhabit tropical and subtropical waters worldwide, often forming mixed schools with other small tunas. The distinctive wavy lines on their backs become less prominent toward the tail, helping distinguish them from Bullet tuna during careful examination.

These fast-swimming predators feed on small fish, squid, and planktonic crustaceans. In many Pacific islands, Frigate tuna provide important protein for local communities, caught by traditional methods. While too small for most industrial operations, they make excellent light-tackle gamefish and good eating when prepared fresh. Some regions dry or smoke them as preserved protein sources. The IGFA world record weighed 11 pounds 11 ounces.

5. Kawakawa (Euthynnus affinis)

Kawakawa, also known as Mackerel tuna or Little Tuna in some regions, inhabits Indo-Pacific waters from the Red Sea to Australia and across to Japan. These medium-sized tunas (up to 50 pounds) display distinctive broken wavy lines on their backs above the lateral line. They prefer coastal waters and often enter large bays and harbors in search of prey, unusual behavior among tunas.

In Southeast Asian and Indian Ocean countries, Kawakawa support important artisanal fisheries. The meat, darker and stronger-flavored than most tunas, works well in curries and heavily spiced dishes where the flavor complements rather than competes. Fresh Kawakawa makes acceptable sashimi, though it lacks the refined taste of premium species. They're often confused with Little Tunny but occupy different geographic ranges. The IGFA record stands at 40 pounds 5 ounces.

6. Longtail/Tongol Tuna (Thunnus tonggol)

Longtail tuna, found exclusively in Indo-Pacific waters, represent one of the smaller true tunas within genus Thunnus. Growing to about 130 pounds, they inhabit coastal waters from the Arabian Gulf to Australia and throughout Southeast Asia. Their elongated tail fin gives them their common name, and they're easily distinguished from other tunas by this feature combined with their strictly coastal habitat preference.

These tuna often enter estuaries and river mouths, highly unusual behavior for the family that demonstrates their adaptability. In Australia and throughout Southeast Asia, Longtail support recreational and small commercial fisheries. The meat quality varies with handling but can be excellent when fresh and properly bled. They're marketed as "Northern Bluefin" in Australia, though they're taxonomically distinct from true Bluefin species. The IGFA world record weighed 79 pounds 3 ounces, caught in India.

7. Little Tunny (Euthynnus alletteratus)

Little Tunny, often mislabeled as "false albacore" or simply "bonito," inhabit Atlantic waters from New England to Brazil. These small tunas (up to 35 pounds) display distinctive wavy lines on their backs and characteristic spots below the pectoral fins. They form large schools near the surface, creating spectacular feeding frenzies that attract seabirds, predators, and anglers alike.

While abundant and eager to strike lures, Little Tunny have bloody, strong-flavored meat that many find unpalatable without specific preparation techniques. However, they're excellent as cut bait for larger gamefish or when bled immediately after capture and prepared properly. Sport fishermen appreciate their abundance and spirited fighting ability, making them popular targets for light tackle and fly fishing enthusiasts. The IGFA record stands at 36 pounds 1 ounce.

8. Slender Tuna (Allothunnus fallai)

Slender tuna remain the most mysterious of all tuna species, found only in the cold waters of the Southern Ocean surrounding Antarctica. These rare fish reach about 80 pounds and have extremely elongated, almost mackerel-like bodies compared to other tunas. Their adaptation to near-Antarctic waters makes them unique among the Thunnini, which typically prefer much warmer seas.

Very little is known about Slender tuna biology or behavior due to their remote habitat and extreme rarity. They occasionally appear as bycatch in Southern Ocean toothfish and krill fisheries but have no commercial importance. Scientists believe they feed on deep-water fish and squid, but much about their ecology, reproduction, and population status remains unknown. Their extreme habitat provides natural protection from fishing pressure.

Tuna Fishing Techniques: How to Catch Each Species

For anglers seeking these magnificent fish, understanding species-specific techniques dramatically improves success rates. Each tuna type responds differently to baits, lures, and fishing methods based on their feeding habits, depth preferences, and behavior patterns. Here's your guide to targeting each species effectively.

Surface School Tactics: Skipjack and Little Tunny

Skipjack and Little Tunny form massive surface schools that create visible signs from considerable distances. Look for diving birds, surface splashing, or "jumpers" breaking the water. These visual cues indicate feeding activity where predators push bait to the surface. Fast-retrieved lures work best, with small feather jigs, Clark spoons, and surface poppers producing consistent results. Light tackle in the 20-30 pound range provides maximum sport while handling these smaller species effectively.

Chumming with live or frozen bait brings schools within casting distance when they're passing through an area. Anchovies, sardines, or squid chunks create scent trails that attract these opportunistic feeders. Once the school appears, cast metal jigs or small lures into the frenzy and retrieve rapidly with an erratic action that mimics panicked baitfish. Live bait options for these species include small sardines, anchovies, and squid strips fished on light wire leaders.

Trolling Methods: Albacore, Yellowfin, and Bigeye

Albacore respond exceptionally well to trolled squid lures and small feather jigs at depths of 20-50 feet. Their preference for cooler, deeper water requires downriggers or diving planes to reach optimal feeding zones. Trolling speeds between 5-7 knots match their cruising behavior while searching for squid and small fish. Oregon and California anglers target Albacore specifically during summer months when warm water pushes them northward.

Yellowfin and Bigeye require different approaches based on their depth preferences. Yellowfin often feed near the surface, particularly early morning and evening, responding well to trolled cedar plugs, jet heads, and soft plastic squid chains. Bigeye, however, spend daylight hours in deep water and require specialized techniques. Deep-drop rigs with lights and heavy sinkers reach 100+ feet where Bigeye hunt during the day. At night, both species rise to shallower depths and become more accessible to standard trolling methods.

Bluefin Strategies: The Ultimate Challenge

Catching Bluefin tuna represents the pinnacle of offshore angling. These powerful fish require heavy tackle, often 80-130 pound test line and large conventional reels with substantial line capacity. Tuna lures for Bluefin include large jet heads, spreader bars, and soft plastic squid imitations trolled at 6-8 knots. Live baiting with mackerel, herring, or squid produces exceptional results when Bluefin are concentrated around structure or feeding aggregations.

Drift fishing with live bait near known Bluefin haunts, including offshore banks, temperature breaks, and current edges, puts you in position for these giants. Electronic monitoring of water temperature, chlorophyll concentrations, and current patterns helps locate productive areas. Chumming with live baitfish creates a sustained feeding frenzy that can bring Bluefin within range. Patience and preparation are essential, as battles with large Bluefin can last hours.

Inshore Minor Species: Blackfin, Black Skipjack, and Kawakawa

Blackfin Tuna stay within continental shelf waters, making them accessible to anglers fishing from smaller boats or even piers and jetties in Florida and the Caribbean. Light spinning tackle with 15-20 pound test line provides excellent sport. Small metal jigs, diving plugs, and live pilchards or sardines produce consistent action. These aggressive feeders strike quickly, requiring alertness and fast hooksets.

Black Skipjack and Kawakawa prefer coastal waters where structure concentrates baitfish. Fishing around reefs, wrecks, and drop-offs with diving lures or live bait accounts for most catches. In the Eastern Pacific and Indo-Pacific regions respectively, these species provide exciting light-tackle opportunities without requiring extensive offshore runs. Fly fishermen particularly enjoy targeting these accessible tunas with baitfish patterns and popping bugs.

Visual Identification Guide: How to Tell Tuna Species Apart?

Key Physical Features for Each Species

Accurate identification of types of tuna fish pictures requires attention to specific anatomical details. The most reliable markers include pectoral fin length, body proportions, and coloration patterns. Albacore's extraordinarily long pectoral fins extend well past the second dorsal fin, creating an unmistakable silhouette. Yellowfin display bright yellow second dorsal and anal fins that become increasingly sickle-shaped as the fish mature.

Bluefin species share robust, football-shaped bodies but differ in subtle ways. Atlantic Bluefin have the shortest pectoral fins relative to body size, while Pacific Bluefin show proportionally smaller eyes. Southern Bluefin fall between these extremes with moderate fin proportions. Size provides a strong clue for large specimens: any tuna exceeding 1,000 pounds is almost certainly an Atlantic Bluefin, as no other species regularly achieves such massive dimensions.

Color Patterns and Markings

Color patterns provide crucial identification clues for the complete list of tuna fish species. Skipjack's horizontal belly stripes remain unique among commercial tunas, creating immediate recognition. Little Tunny and Kawakawa share wavy dorsal patterns but differ in ventral spotting: Little Tunny displays distinct spots between pectoral and ventral fins, while Kawakawa lacks these markings entirely.

Minor species often show more distinctive patterns than true tunas. Black Skipjack displays dark oblique stripes on its back, while Bullet and Frigate tunas share similar wavy lines but differ in body proportions and maximum size. Fresh specimens display colors more vividly, as these patterns fade relatively quickly after death. Water temperature and depth also influence coloration intensity, with fish caught in deeper, colder water often showing more vibrant markings.

Fin Characteristics

Fin shape and size offer reliable identification features across all tuna species. Beyond Albacore's famous elongated pectorals, other species show distinctive fin characteristics. Yellowfin's second dorsal and anal fins grow disproportionately with age, becoming curved and elongated in mature specimens. Bigeye's fins remain proportional throughout life, helping distinguish them from similar-sized Yellowfin that may grow alongside them.

The number and color of finlets, those small fins between the main dorsal/anal fins and the tail, also aid identification. Most species possess 7-10 finlets, but their coloration varies systematically. Bluefin species typically show yellow finlets with black edges, while Yellowfin display bright yellow finlets matching their larger fins. Blackfin's namesake black fins immediately distinguish them from other small tunas. Combined with body shape, size, and other coloration, these fin details enable accurate species identification even with processed fish.

Best Tasting Tuna Species: Culinary Guide

Ranking Tuna by Flavor Profile

When evaluating the best tasting tuna species, three factors dominate: flavor complexity, texture, and fat content. Bluefin species universally top culinary rankings, with Atlantic Bluefin's otoro (fatty belly) representing the absolute pinnacle of tuna cuisine. Southern and Pacific Bluefin follow closely, offering similar richness with subtle regional variations. These premium species deliver complex umami notes and truly buttery textures that justify their astronomical prices.

Bigeye ranks just below Bluefin, providing excellent marbling and rich flavor at more accessible price points. Its deep red meat and high fat content create outstanding sashimi experiences. Yellowfin offers versatility with its mild, slightly nutty flavor that appeals to Western palates while maintaining authenticity for Japanese preparations. Albacore's light, delicate taste suits those preferring subtle seafood flavors, while Skipjack's stronger, more assertive profile works best in prepared dishes rather than raw applications.

Sushi Terminology: Understanding Maguro, Toro, and Grades

Navigating sushi menus requires understanding specific terminology that describes cuts and quality levels. The term "maguro" broadly refers to tuna in Japanese, but precision matters when ordering or evaluating quality. Here's your guide to sushi tuna terminology:

Akami refers to the lean red meat from the top of the fish, along the spine. This cut offers pure, clean tuna flavor without significant fat content. It represents the most commonly served sushi cut and provides the characteristic red color most people associate with tuna. Bluefin akami commands premium prices due to superior texture and flavor complexity compared to other species.

Chutoro comes from the upper belly section and represents medium-fatty meat with visible marbling. This cut balances lean meat with enough fat to create a rich, melt-in-your-mouth experience without the overwhelming richness of the fattiest sections. Chutoro offers an excellent introduction to fatty tuna for those new to premium sushi, providing noticeable improvement over akami without the intensity (and price) of the highest grade.

Otoro represents the fattiest portion from the lower belly, featuring extensive marbling that appears almost white with pink striations. This ultra-rich cut literally melts on the tongue, delivering an unmatched luxurious texture and complex flavor profile. True otoro comes only from large, mature Bluefin tuna, explaining its extraordinary cost. The best otoro comes from wild fish during winter months when fat content peaks.

Toro serves as a general term encompassing both chutoro and otoro, referring to any fatty belly cut. When you see "toro" on a menu without specification, ask whether they mean chutoro or otoro, as the price and experience differ significantly. Some restaurants also offer "negitoro," a chopped mixture of fatty belly meat and green onion served as a hand roll filling or topping.

Sushi-grade and sashimi-grade designations indicate fish handled specifically for raw consumption, though these terms lack legal definition in many countries. True sushi-grade tuna undergoes flash-freezing to -20°C or below to eliminate parasites, followed by careful handling to prevent bacterial contamination. When purchasing tuna for home sushi preparation, seek suppliers who specifically designate "sushi-grade" and can explain their handling protocols.

Best Species for Sushi and Sashimi

For sushi and sashimi, fat content and texture quality matter more than any other factors. Atlantic Bluefin provides incomparable quality across all cuts, with the progression from akami through chutoro to otoro offering distinct experiences. Bigeye serves as an excellent Bluefin substitute, particularly for chutoro-style preparations where its natural marbling shines. Bigeye's deep-diving habits create meat texture that rivals premium Bluefin at significantly lower cost.

Yellowfin, marketed as "ahi," dominates mid-range sushi establishments. Its cleaner flavor and firmer texture appeal to Western palates while maintaining Japanese culinary authenticity. Young Bluefin called "meji" offers developing Bluefin flavor at accessible prices, though lacking mature fish's marbling. For sustainable sushi choices, carefully sourced pole-caught Yellowfin or well-handled Albacore provide excellent alternatives without supporting overfished Bluefin populations.

Ideal Tuna for Grilling and Steaks

Grilling demands tuna with sufficient fat to prevent drying during high-heat cooking. Yellowfin steaks remain the most popular choice for grilling, offering the perfect balance of flavor, texture, and moisture retention. Cut at least 1 inch thick and seared quickly over high heat, Yellowfin develops a beautiful caramelized crust while maintaining a rare, tender center. Marinate briefly in soy sauce, sesame oil, and ginger, or simply season with salt and pepper to let the fish speak for itself.

Albacore, despite lower fat content, grills excellently when cooked carefully and not left on the heat too long. Its firm texture holds up to marinades and bold seasonings that might overwhelm more delicate fish. Even Skipjack, typically reserved for canning, can be grilled fresh in coastal communities where it's landed daily. The keys to successful tuna grilling are high heat, short cooking time, and starting with quality fresh fish rather than previously frozen products.

Canned Tuna Varieties Explained

The canned tuna market divides primarily between "light" and "white" varieties, with important differences in species, flavor, and nutrition. Light tuna, predominantly Skipjack with some Yellowfin, offers stronger flavor and softer texture at economical prices. Its darker meat and smaller flakes suit sandwiches, salads, and casseroles where the tuna flavor should assert itself. Chunk light provides smaller, irregular pieces, while solid light maintains larger, more intact sections.

White tuna exclusively uses Albacore, providing milder flavor and firmer, lighter-colored meat. Its larger flakes and steak-like texture appeal to consumers seeking less assertive fish taste. Solid white Albacore commands premium prices, offering chunks that resemble fresh-cooked tuna more than traditional canned products. Some specialty brands now offer Yellowfin and even Tongol (Longtail) tuna, expanding options beyond traditional choices.

Oil-packed varieties provide richer flavor and better moisture retention, while water-packed options reduce calories and allow more control over added ingredients. "Dolphin-safe" labels indicate fishing methods designed to minimize dolphin bycatch, an important consideration for environmentally conscious consumers. Looking for pole-and-line caught or troll-caught certifications ensures more sustainable fishing practices with lower ecosystem impacts.

Tuna Nutrition and Mercury: Complete Safety Guide

Nutritional Comparison by Species

Tuna provides exceptional nutritional value across all species, delivering high-quality protein, omega-3 fatty acids, and essential vitamins with minimal saturated fat. However, nutritional profiles vary between species based on fat content, diet, and habitat. Here's how the main commercial species compare nutritionally per 3-ounce cooked serving:

Species	Calories	Protein	Omega-3 (g)	Fat (g)	Selenium (%DV)
Skipjack	112	25g	0.3	1g	85%
Albacore	128	26g	0.7	2g	95%
Yellowfin	118	25g	0.3	1g	90%
Bigeye	130	25g	0.4	2g	88%
Bluefin	156	25g	1.3	5g	108%

All tuna species excel as protein sources, providing complete amino acid profiles that support muscle maintenance and growth. The high selenium content supports thyroid function and provides antioxidant benefits. Vitamin B12, niacin, and vitamin B6 appear in significant amounts across all species, supporting energy metabolism and neurological health.

Bluefin species contain the highest omega-3 fatty acid levels due to their greater fat content, with Atlantic Bluefin providing over four times the omega-3s of leaner species. These essential fatty acids support cardiovascular health, reduce inflammation, and promote brain function. However, the higher fat content that provides these benefits also concentrates mercury, creating a trade-off between nutritional benefits and potential risks.

Mercury Levels by Species: Specific PPM Data

Mercury contamination represents the primary health concern when consuming tuna, with levels varying dramatically between species based on size, age, diet position, and habitat. The FDA monitors mercury in commercial fish and provides specific concentration data measured in parts per million (ppm). Here are the documented mercury levels for the main commercial species:

Species	Mercury (ppm)	FDA Category	Safe Servings/Week
Skipjack	0.126	Best Choices	2-3 servings
Yellowfin	0.354	Good Choices	1 serving
Albacore	0.350	Good Choices	1 serving
Bigeye	0.689	Choices to Avoid	Avoid
Bluefin	0.600+	Choices to Avoid	Avoid

Skipjack contains the lowest mercury levels among commercial tunas at 0.126 ppm, roughly one-third the concentration found in Albacore and Yellowfin. This makes Skipjack the safest choice for frequent consumption, particularly for vulnerable populations. The low mercury levels result from Skipjack's small size, short lifespan (8-12 years vs 40+ for Bluefin), and lower position in the food chain.

Bigeye contains the highest mercury among commonly consumed tunas at 0.689 ppm, over five times Skipjack's level. Their deep-diving behavior exposes them to mercury-concentrating prey in the mesopelagic zone, while their longer lifespan allows greater bioaccumulation. Bluefin species show similarly elevated mercury at 0.600+ ppm, with larger, older fish potentially containing even higher concentrations. The FDA explicitly recommends pregnant women and young children avoid both Bigeye and Bluefin tuna entirely.

FDA and EPA Consumption Guidelines

The U.S. Food and Drug Administration and Environmental Protection Agency jointly issue seafood consumption guidelines to help Americans balance nutritional benefits against mercury risks. These recommendations categorize fish into three groups based on mercury content and provide specific serving guidance for different populations.

"Best Choices" category includes fish with mercury levels below 0.15 ppm. Skipjack tuna falls into this group, making it the only tuna species recommended for frequent consumption. The FDA advises eating 2-3 servings per week of Best Choices fish for most adults. Other low-mercury options include salmon, sardines, and tilapia, allowing variety even when limiting higher-mercury species.

"Good Choices" category includes fish with mercury between 0.15-0.46 ppm. Both Yellowfin (0.354 ppm) and Albacore (0.350 ppm) fall into this category. The FDA recommends limiting Good Choices fish to one serving weekly for most adults. For pregnant women, breastfeeding mothers, and young children, the recommendation drops to just one serving per week total across all Good Choices species combined.

"Choices to Avoid" category includes fish exceeding 0.46 ppm mercury. Bigeye (0.689 ppm) and all Bluefin species (0.600+ ppm) fall into this group. The FDA explicitly advises pregnant women, nursing mothers, and young children to completely avoid these fish. Other adults should consume them rarely, treating them as occasional indulgences rather than dietary staples. King mackerel, shark, swordfish, and tilefish join tuna in this high-mercury category.

A standard serving equals 4 ounces for adults and 2 ounces for children under age 11. These portions provide nutritional benefits while limiting mercury exposure to acceptable levels. Pregnant women should pay particular attention to these guidelines, as mercury can harm developing nervous systems even at low exposure levels. For those concerned about mercury but wanting tuna's benefits, choosing Skipjack and limiting other species provides the safest approach.

Tuna Species by Geographic Location

Atlantic Ocean Species

The Atlantic Ocean hosts seven tuna species, with several found exclusively in these waters. Atlantic Bluefin, the ocean's giant, migrates seasonally from spawning grounds in the Mediterranean and Gulf of Mexico to feeding areas as far north as Norway and Canada. This extensive range makes them accessible to anglers and commercial fishermen across multiple continents, though strict quotas now limit catches significantly.

Blackfin tuna remain unique to the Western Atlantic, preferring warm waters from Massachusetts to Brazil with particular abundance in the Caribbean and Gulf of Mexico. These smaller true tunas often school with Skipjack in tropical areas, providing exciting light-tackle opportunities. Little Tunny dominates near-shore Atlantic waters from New England to Brazil, forming massive schools that create spectacular surface feeding activity visible from great distances.

Albacore populations in the Atlantic remain separate from Pacific stocks, following distinct migration patterns that bring them to European and North American waters seasonally. Yellowfin and Bigeye occupy tropical Atlantic waters year-round, while Skipjack shows the widest distribution, from temperate to tropical zones across the entire basin. This diversity makes the Atlantic a prime destination for tuna anglers seeking multiple species.

Pacific Ocean Species

The Pacific Ocean contains the greatest tuna diversity, hosting all 15 species across its vast expanse. Pacific Bluefin spawn exclusively in the Western Pacific near Japan, with juveniles undertaking one of nature's most impressive migrations across the entire ocean to feeding grounds off California and Mexico. Black Skipjack exists only in the Eastern Pacific, from Southern California to Peru, representing a regional endemic species.

The warm Kuroshio Current off Japan and California Current off North America create ideal conditions for multiple species. Yellowfin reaches its largest sizes in the Pacific, particularly around Hawaiian seamounts and offshore banks where food is abundant. The Pacific's vast expanse allows different populations of the same species to develop unique characteristics, creating distinct genetic stocks important for fishery management.

Kawakawa and Longtail tuna inhabit the Indo-Pacific region exclusively, supporting important artisanal fisheries from East Africa to Australia. The Western and Central Pacific Fisheries Commission manages the world's largest tuna fishery, producing 55% of global tuna landings. Understanding Pacific tuna distribution helps anglers plan trips, as seasonal patterns concentrate fish in predictable areas based on temperature, current, and food availability.

Indian Ocean Species

The Indian Ocean supports substantial tuna fisheries, particularly for Skipjack and Yellowfin that dominate commercial landings. The Arabian Sea and Bay of Bengal host important spawning grounds for multiple species, with seasonal monsoon patterns dramatically affecting distribution and availability. Southern Bluefin migrate through the southern Indian Ocean, following productive feeding areas between Australia and South Africa.

Kawakawa thrives in coastal areas from the Red Sea to Western Australia, supporting small-scale fisheries throughout the region. Longtail tuna show particular abundance in the northern Indian Ocean, often entering the Persian Gulf and other shallow seas. Bigeye populations in the Indian Ocean face particular pressure from industrial fishing, leading to conservation concerns about stock sustainability and the need for stricter management measures.

The Indian Ocean Tuna Commission coordinates management across this vast and complex fishery, balancing the needs of coastal developing nations with distant-water fishing fleets. Climate change impacts on monsoon patterns and ocean temperatures create uncertainty about future tuna distribution, requiring adaptive management approaches. For anglers, the Indian Ocean offers exceptional opportunities for multiple species, particularly in the Maldives, Seychelles, and along East African coasts.

Species Found in Multiple Oceans

Several tuna species maintain truly global distributions across ocean basins. Skipjack, Yellowfin, and Bigeye inhabit all three major oceans, though genetic studies reveal distinct populations that rarely mix. This cosmopolitan distribution makes them the backbone of global tuna fisheries, with landings from multiple regions supplying worldwide markets. Albacore shows similar widespread distribution but tends to avoid the warmest equatorial waters, preferring temperate zones.

Bullet and Frigate tunas occur worldwide in tropical waters, though their small size makes them commercially insignificant despite their abundance. Understanding these distribution patterns helps predict where to find specific species and informs international management efforts requiring cooperation between nations. Climate change increasingly affects these patterns, with species ranges shifting poleward as ocean temperatures rise, potentially creating new fishing opportunities in some areas while reducing them in others.

Conservation Status of Different Tuna Types

Endangered and Vulnerable Species

The conservation status of different types of tunas varies dramatically by species, reflecting their biology, fishing pressure, and management effectiveness. Atlantic Bluefin faced near-extinction from decades of overfishing but shows encouraging recovery under strict international management. Pacific Bluefin remains critically endangered, with populations estimated at less than 3% of historical unfished levels. Southern Bluefin, while improving under quota systems, stays listed as endangered due to past overfishing impacts.

Bigeye tuna populations declined significantly across much of their range, earning a "vulnerable" designation from the IUCN. Some regional Yellowfin stocks, particularly in the Indian Ocean, approach overfished status requiring management intervention. These designations reflect decades of industrial fishing pressure combined with biological characteristics that make recovery slow: large size, late maturity, and long lifespans that concentrate fishing mortality on reproductive individuals.

Smaller species generally fare better conservation-wise due to faster reproduction. Skipjack, Albacore, and most minor species maintain healthy populations with sustainable harvest levels. Tuna conservation history demonstrates both the damage humans can inflict on marine populations and our capacity for recovery when science-based management prevails over short-term economic pressures.

Sustainable Tuna Choices

Skipjack represents the most sustainable tuna choice for regular consumption, with healthy populations, rapid growth, and early maturity enabling stable harvests under current fishing pressure. Pole-and-line caught Albacore from the Pacific provides another responsible option, with fishing methods that minimize bycatch and ecosystem impacts compared to industrial purse seining or longline operations.

The Marine Stewardship Council certifies several tuna fisheries meeting strict sustainability criteria for stock health, ecosystem impacts, and management effectiveness. Looking for the blue MSC label helps consumers identify responsibly sourced options. Some Yellowfin fisheries, particularly those avoiding Fish Aggregating Devices (FADs), maintain sustainability certifications worth seeking out. Small-scale fisheries using traditional methods often provide the most sustainable options while supporting coastal communities.

"Dolphin-safe" labels indicate compliance with practices designed to minimize dolphin mortality during purse seine fishing, an important ethical consideration. "Pole and line caught" or "troll caught" designations indicate selective methods with lower bycatch of sea turtles, sharks, and other vulnerable species. Even within species, fishing method and location dramatically affect sustainability, making label reading a valuable habit for conscientious consumers.

Global Catch Statistics

Global tuna catches reached approximately 5.2 million metric tons annually in recent years, with Skipjack comprising 58% and Yellowfin 29% of total landings. These two species account for an overwhelming 87% of commercial tuna fishing. Albacore contributes 7%, while Bigeye represents 5% of global catch. All Bluefin species combined account for less than 1% due to conservation measures, their relative rarity, and extraordinarily high value that limits harvest even where legal.

Regional fishery management organizations (RFMOs) monitor stocks and set quotas based on scientific assessments that ideally balance economic needs with biological sustainability. The Western and Central Pacific produces 55% of global tuna, followed by the Indian Ocean at 22% and the Atlantic at 12%. Purse seine vessels catch 66% of tuna globally, while longline fishing accounts for 11% and pole-and-line methods capture 8%. Understanding these statistics helps contextualize individual species' conservation needs and fishing pressure.

Climate change increasingly affects tuna distribution and abundance, with species moving poleward as waters warm. This creates management challenges as fish shift between jurisdictional boundaries and into areas with less monitoring and enforcement capacity. International cooperation through RFMOs remains essential for ensuring these valuable resources persist for future generations of fishermen, seafood lovers, and marine ecosystem health.

Frequently Asked Questions

Conclusion

The world of types of tuna extends far beyond the few varieties most people recognize at the grocery store or sushi bar. From the colossal Atlantic Bluefin that can exceed a ton to the tiny Bullet tuna barely larger than a sardine, these 15 species showcase extraordinary diversity in size, habitat, behavior, and culinary applications. Understanding these differences empowers you to make informed choices whether you're planning a fishing expedition, selecting sushi, or simply shopping for a healthy protein source.

Each species plays a unique role in marine ecosystems and human culture. While Skipjack supports massive global industries sustainably, Pacific Bluefin faces critical conservation challenges requiring careful consumer choices. By selecting pole-and-line caught options, avoiding overfished species, and following FDA guidelines for mercury consumption, you contribute to both ocean health and personal wellbeing.

This comprehensive guide serves as your complete reference for tuna in 2026. Whether you're identifying a catch, selecting the perfect species for dinner, researching IGFA records, or simply satisfying curiosity about these remarkable fish, you now possess the knowledge to distinguish all 15 types of tuna and make informed decisions about their consumption and conservation. The ocean's greatest athletes deserve both our appreciation and our stewardship.