Toro runs a bit over a quarter fat by weight. Japanese food composition tables list 27 to 28 percent fat for it, against about 1.3 percent in the lean dorsal muscle of bluefin (about 1.1 percent averaged with yellowfin), according to a 2024 peer-reviewed analysis of raw tuna muscle.
That fat is the whole appeal. The meat comes from the fatty belly of bluefin, it melts on the tongue, and it is served as nigiri or sashimi at the top of the maguro price scale.
Sushi chefs divide the belly into chutoro and otoro. Akami, the lean red meat, is the cut people compare them with.
What is toro sushi?
The name comes from torori, a Japanese word for melting on the tongue (Sushi-Pedia, 2025). Sushi Walker credits a regular at Yoshino Sushi Honten with coining it, replacing the older term abu.
What you get is raw tuna belly, and the fat is the point.
Toro is one of two categories of maguro, the Japanese word for tuna. Akami, the lean red meat, is the other. Order plain maguro and the plate is akami, per SushiFAQ. Toro has to be requested by name.
Most diners meet it as a slice pressed onto vinegared rice as nigiri. Sushi bars also cut thicker slices and serve them as plain sashimi, with no rice underneath.
Minced toro mixed with green onion is called negitoro, and it shows up in rolls and as a rice-bowl topping (Wikipedia).
The word doesn’t always mean tuna, either. Beni toro is the fatty belly of sockeye salmon, and toro katsuo is a fatty cut of bonito. Sushi-Pedia lists both as toro. Wikipedia adds that the term has no exact boundary and that sellers use it as a luxury signal.
Which part of the tuna is toro, and what are the grades?
Chutoro (medium fat) and otoro (the fattiest) are the two toro grades, and both come from the belly. Akami, the lean loin along the spine, is the contrast cut and does not count as toro.
| Cut | Position | Fat level | Typical role |
|---|---|---|---|
| Akami | Loin along the spine | Lowest | Standard maguro nigiri and sashimi |
| Chutoro | Between akami and otoro, belly and back near the skin | Medium | Nigiri and sashimi |
| Otoro | Front belly, just behind the head | Highest | Special-occasion nigiri and sashimi |
| Kamatoro | Collar behind the gills | High, close to otoro | Nigiri topping |
Fat follows position. It runs higher in the belly than the back, in the front than the rear, and in the surface layers than the deep ones, according to Sushi Walker.
Dorsal bluefin muscle sits at about 1.3% fat. Japanese food composition tables list 27 to 28% for toro, per a 2024 peer-reviewed analysis of raw tuna muscle.
Published figures for the grades don’t match each other. Yuzu Omakase (2026) puts chutoro at 15 to 20 percent and otoro at 25 to 30 percent, climbing close to 40 percent at the winter peak.
Wikipedia notes that fat varies with where the tuna was caught and when. Treat any single percentage as one reading, not a standard.
Otoro
Otoro is the fattiest belly cut. It sits at the front belly, just behind the head, and looks pale pink, nearly white where the marbling is dense. Tasting Table says it is priced as the top cut of the maguro.
Shimofuri is the rarest toro. It comes from the belly and collar area and shows thin lines of fat through the meat, and ordinary sushi restaurants rarely serve it (Wikipedia).
Chutoro
Chu means middle, and the cut sits between akami and otoro. It is taken from the belly and from the back close to the skin.
The Takeout points out that a tuna yields far less chutoro than akami, which is why it costs more.
No measured boundary separates chutoro from otoro, Yuzu Omakase notes.
Kamatoro
Kamatoro comes from the collar, the kama muscle that runs from the gill cover to the pectoral fin. Its fat rivals otoro, and Sushi Walker lists it as a popular nigiri topping.
Butchers class the collar with trim (ara), so it sits outside the main fillet blocks.
What does toro taste like?
Toro tastes rich and a little sweet, and the texture is so soft there’s hardly any chewing involved. It’s buttery, which is the word nearly everyone reaches for.
Fat laced through the muscle shows as visible marbling. It softens at mouth temperature, so a slice loosens within seconds.
Akami is the clean, meaty one, with an iron tang (Kisetsu), and chutoro is smooth, semi-sweet, umami-rich and never oily (Yuzu Omakase). Otoro goes furthest, with fat that coats the tongue.
That coating has a practical side. Otoro eaten first flattens the akami that follows, which is why counters run from lean to fat.
Wild winter tuna carries more fat than summer fish (Wikipedia). In a study of 150 Pacific bluefin from the Yaeyama Islands in southern Japan, fat content and auction price both fell steadily from early April to early July (Shimose et al., Fisheries Research, 2018).
Spawning draws the fat down. A fish that tastes superb in January can be ordinary by June.
Which tuna species does toro come from?
Bluefin tuna, mostly. Wikipedia names Pacific bluefin as the usual source and bigeye as the other tuna with similar fatty meat. Atlantic and southern bluefin get sold as toro too.
Pacific bluefin (Thunnus orientalis) is the benchmark for Japanese toro. In Japan it goes by kuro-maguro or honmaguro (“true tuna”), per Tasting Table.
Atlantic bluefin (Thunnus thynnus) has a maximum published weight of 684 kg (FishBase also cites unverified reports up to 900 kg) and a maximum reported age of 32 years, with lifespans up to 40 years cited for the western Atlantic (FishBase).
Southern bluefin (Thunnus maccoyii) spreads across a southern circumpolar band. Its only known spawning area is southeast of Java, according to the CCSBT biology report republished by the IOTC in 2023.
NOAA Fisheries reports that Pacific bluefin mature at about 5 years, live up to 26 and average about 15, with the largest geographic range of any tuna. NOAA lists the maximum reported size at 3 m and 450 kg.
Menu labels do not settle the species question. SushiFAQ notes that yellowfin can also be sold as maguro, because most countries have no legal standard for the word.
Why is toro so expensive?
Supply limits and the cost of the whole fish drive the everyday price. The record numbers in the news mostly measure something else, which is auction publicity.
A bluefin carries bone, skin and trim that never sell as toro, so the belly cuts carry the cost of the entire fish.
Regional commissions cap bluefin landings, and many Japanese fishermen were close to their 2026 large-fish limit after a heavy spring run (Baird Maritime, 2026). On the auction side, SeafoodSource called the first sale of the year largely a yearly publicity move for the winning bidder.
Kiyomura Corp., which runs the Sushi Zanmai chain, bought the 2026 record fish at Toyosu on 5 January. It was caught off Oma in Aomori Prefecture (AP).
Set that against the dockside market and the gap is huge. NOAA’s 2024-2025 report on Atlantic highly migratory species puts the average Atlantic bluefin price at $6.12 per pound dressed weight, so the auction fish sold for roughly a thousand times more per pound.
The species and weight basis differ, yet no adjustment closes a gap that size.
The record first-auction price was 510.3 million yen (about US$3.2 million) for a 243 kg bluefin, up from 333.6 million yen in 2019 (AP and SeafoodSource, January 2026). The average dockside price for Atlantic bluefin was $6.12 per pound dressed weight in 2024 (NOAA Fisheries). Calculated from those two figures, the gap per pound is roughly 1,000 times.
Is toro healthy, and how much mercury does it carry?
How often you eat it matters more than any single piece. Toro is concentrated omega-3 fat and calories, and bluefin as a group accumulates mercury.
Fat, calories and omega-3
Published nutrition values for bluefin disagree because they describe different cuts. NOAA lists one entry for raw Pacific bluefin, while the Southern Bluefin Tuna Industry Association splits its table into fatty and non-fatty cuts.
NOAA FishWatch gives raw Pacific bluefin at 144 calories and 4.9 g total fat per 100 g. The industry association’s table shows 3.5 g fat per 100 g raw for the non-fatty cut and 28.3 g for the fatty cut.
The fatty cut also carries far more EPA and DHA than the non-fatty one in that table.
Toro sits with the fatty cut, so the single NOAA figure understates it.
Mercury
A PNAS study describes bluefin as long-lived apex predators that accumulate high levels of methylmercury (Tseng et al., 2021).
Origin shifts the number inside one species. In Pacific bluefin, fish freshly arrived from the western Pacific carried more mercury in white muscle than fish that had lived longer off California, according to a USGS publication (Colman et al., 2015).
Wild and farmed fish differ as well. A Mediterranean study of Atlantic bluefin found wild fish averaging 1.7 mg/kg of mercury against 0.6 mg/kg for farmed fish, with a 1 mg/kg limit for predatory fish (Molecules, 2019).
The cut adds a wrinkle. A 2023 paper in Foods recounts that total mercury in farmed Pacific bluefin falls when lipid content is extremely high. That finding comes from farmed fish, so it is a lead, not a rule.
The FDA and EPA advice chart (updated January 2017) lists bigeye tuna under Choices to Avoid. Anyone pregnant, breastfeeding or feeding young children should follow that guidance and ask a clinician about bluefin specifically.
Is toro sustainable?
It depends on the species and the fishery. In its September 2021 update IUCN rated Atlantic bluefin Least Concern and southern bluefin Endangered, with Pacific bluefin Near Threatened in between, and rating bodies still disagree on the Pacific stock.
| Species | IUCN status (September 2021) | Previous status |
|---|---|---|
| Atlantic bluefin | Least Concern | Endangered |
| Pacific bluefin | Near Threatened | Vulnerable |
| Southern bluefin | Endangered | Critically Endangered |
IUCN credited regional fishing quotas for the recovery of four commercially fished tuna species in that update.
ICCAT raised the total allowable catch for both Atlantic bluefin stocks for 2026 to 2028 at its November 2025 meeting in Seville. Enforcement still slips. NOAA reported that U.S. landings exceeded the adjusted quota in 2024, which left no underharvest to carry into 2025 (The Fisherman, April 2025).
Why ratings for Pacific bluefin disagree
Pacific bluefin is the species where the verdicts split.
The ISC 2024 assessment says the stock is not overfished and has passed its second rebuilding target, per WCPFC Northern Committee papers. Seafood Watch, on 7 October 2024, issued its first yellow ratings for Eastern Pacific fisheries, limited to FAD-free purse seine in California and Mexico and to US pole-and-line. The Marine Conservation Society, updated January 2026, still calls the stock overfished, with fishing pressure too high and bycatch concerns around purse seine catch.
Stock assessments measure biomass. Rating schemes also weigh gear, bycatch and fishing pressure, and the IUCN listing predates the 2024 assessment.
Does farmed bluefin help?
Only one of the two farming models relieves pressure on wild stock. Capture-based farming grows wild-caught fry in pens, which the Government of Japan’s We Are Tomodachi magazine (2018) calls ineffective for preserving resources.
Full-cycle farming breeds fish from egg to adult in captivity. Kindai University produced the first fully farmed Pacific bluefin in June 2002, and Maruha Nichiro closed the cycle in 2010 before its first commercial shipment in 2015 (Global Seafood Alliance).
Output has since faltered. Fully farmed fish fell from about 3,000 tons (16% of shipments) in 2020 to 405 tons, 2% of Japan’s 18,687 tons of farmed bluefin shipments, in 2024. Kyokuyo (spelled “Gokuyo” in the report) and Nissui withdrew from full-cycle farming, according to Japan Fisheries Agency statistics reported by IB News in 2025.
Full-cycle farming is a real option, but today’s supply is thin.
How should you order toro, and when is another cut the better pick?
Order by cut name, ask for the species and origin, and match the grade to what you want from the piece. Chutoro gives a balanced bite and otoro gives maximum richness. Akami is for a tight budget or for plain tuna flavor.
- Name the cut (chutoro, otoro or kamatoro), because a bare “toro” leaves the grade open.
- Ask which bluefin species it is and whether the fish was wild or farmed.
- Ask where and how it was caught, which is the habit Seafood Watch urged in October 2024.
- Order otoro as a single piece, then decide on a second after tasting it.
- Fall back to akami when the budget is tight or you want clean tuna flavor.
At an omakase counter, where the chef picks every course, the grade is already decided. The useful questions there are about origin and farming.
Many sushi chefs judge a fish by its akami, because lean meat has no fat to hide behind, according to Yuzu Omakase (2026).
Toro is the wrong order on a tight budget, or if you like clean tuna flavor more than fat. It’s also the wrong order during pregnancy, breastfeeding or when feeding young children, unless a clinician clears raw bluefin first. The same goes for diners who weigh stock status heavily and can’t get a straight answer about origin.
Toro Sushi FAQ
Why was toro once thrown away?
Fat spoiled fast, and nothing preserved it before refrigeration. Lean tuna could be marinated in soy sauce as zuke, but the fatty belly did not hold up that way, so cooks often discarded it, according to Sushi Walker.
Wikipedia places the shift toward valuing toro after the Second World War.
Is toro better in winter?
For wild fish, yes. Winter tuna carry more fat, and Japanese fisheries researchers writing in PLOS ONE (2019) found total lipid falling in female Pacific bluefin as the spawning season advanced, with triacylglycerol dropping in the liver and, in Sea of Japan fish, white muscle.
Farmed Pacific bluefin follow their own cycle. Research on farmed Pacific bluefin in Japan reports a drop in muscle fat as the fish mature sexually.
What is negitoro?
Chefs mince toro and mix it with chopped green onion, then use it as a rice-bowl topping, in rolls, and on gunkan sushi.
Is raw toro safe to eat?
Yes, when a reputable supplier handles it correctly. The FDA Food Code requires freezing for most raw fish but exempts several tuna species, including Atlantic bluefin (Thunnus thynnus) and southern bluefin (Thunnus maccoyii).
The exemption does not name Pacific bluefin (Thunnus orientalis) under its current scientific name, so ask how the fish was frozen.
Does “sushi grade” mean anything for toro?
Not as a legal standard. The Takeout calls it a marketing term with no regulated standards behind it, so the label alone does not tell you how a fish was frozen.
Ask the seller for the freezing method and the species name.
Can you buy and slice toro at home?
Yes, with practice. Chef Joel Hammond told The Takeout that beginners should start with akami, whose firm meat is easier to slice.
Buy toro as a saku block from a fishmonger who can say how it was frozen.
Verifying the Cut and Species Behind Your Toro Sushi
Start with the species, since every later answer depends on it. Then ask whether the fish is wild or farmed and from which fishery, and finally ask what paperwork or seal the supplier can show.
Paperwork comes last because it is the only step that confirms the other answers. Southern bluefin exports travel with a CCSBT Catch Documentation Scheme document (in effect since 1 January 2010, replacing the older Trade Information Scheme; CCSBT report republished by the IOTC in 2023), and fully farmed Kindai University fish ship with a seal that also appears on its restaurant menus (Norwegian SciTech News, 2017).
Each of those checks covers one source, not bluefin as a whole. It also slows the order down, and some counters will have no answer to give.
Position verified in October 2026. The ISC plans a health-check assessment for 2027 and its next Pacific bluefin benchmark assessment for 2030, and ICCAT’s current Atlantic bluefin quotas run through 2028, so the preferred origin can change.
