Top 10 Largest Bony Fish by Maximum Weight in the World
The ten heaviest bony fish species, ranked by the maximum published weight in FishBase: sturgeons, ocean sunfishes, marlins, bluefin tuna and swordfish.
Updated October 18, 202610 ranked20 sources
Quick answer
The beluga sturgeon (Huso huso) has the highest maximum published weight of any bony fish: 3,200 kg in FishBase, from a historical record. The giant sunfish is second at 2,744 kg, which is also the heaviest bony fish ever actually weighed and confirmed (Azores, 2021). The sharptail mola is third at 2,000 kg. Ranked by FishBase maximum published weight, as of October 2026.
Sharks and rays (cartilaginous fish) are the true giants of the fish world, so this list covers only bony fish (Osteichthyes). The heaviest bony fish fall into three groups: sturgeons, which can live for a century, the jellyfish-eating ocean sunfishes, and the fast open-ocean predators (marlins, bluefin tuna and swordfish).
Two kinds of 'maximum weight' get mixed up for these fish. One is the maximum published weight that FishBase records for each species, which often comes from historical catches. The other is the heaviest specimen actually weighed and confirmed in a modern study. This list ranks on the first, because FishBase gives a figure for every species. Where a species' FishBase figure is a disputed historical claim, the item says so.
Maximum published weight (kg)
Maximum published weight (kg)
3,200
Beluga sturgeon (Huso huso)
2,744
Giant sunfish (Mola alexandrini)
2,000
Sharptail mola (Masturus lanceolatus)
1,300
Ocean sunfish (Mola mola)
1,000
Kaluga (Huso dauricus)
816
White sturgeon (Acipenser transmontanus)
750
Black marlin (Istiompax indica)
684
Atlantic bluefin tuna (Thunnus thynnus)
650
Swordfish (Xiphias gladius)
636
Blue marlin (Makaira nigricans)
The ranking
1
Beluga sturgeon (Huso huso)
The beluga sturgeon of the Caspian and Black Sea basins is the source of beluga caviar. FishBase gives it a maximum published weight of 3,200 kg and a maximum length of 800 cm, citing Kottelat and Freyhof (2007). The largest specimen most often accepted is smaller: a 1,571 kg female from the Volga estuary in 1827. Claims of 2-3 tonnes are disputed.
Scientific name: Huso husoFamily: Acipenseridae (sturgeons)FishBase max length: 800 cm TLHabitat: Caspian and Black Sea basins (anadromous)
2
Giant sunfish (Mola alexandrini)
The heaviest bony fish ever weighed and confirmed is a giant (bump-head) sunfish found dead off Faial Island in the Azores on 9 December 2021. It weighed 2,744 kg and was 3.25 m long, as published in the Journal of Fish Biology in 2022. The previous record, a 2,300 kg fish caught off Kamogawa, Japan in 1996, was long thought to be an ocean sunfish. A 2017 study showed it was this species.
Scientific name: Mola alexandriniFamily: Molidae (ocean sunfishes)FishBase max length: 325 cm TL (Azores record fish)Habitat: Temperate and tropical oceans
3
Sharptail mola (Masturus lanceolatus)
The sharptail mola is a sunfish with a pointed, tail-like clavus at the back. FishBase gives a maximum published weight of 2,000 kg and a maximum length of 337 cm, both from older literature. Individuals that have been weighed recently are far lighter. One necropsied fish 230.5 cm long weighed 298 kg.
Scientific name: Masturus lanceolatusFamily: Molidae (ocean sunfishes)FishBase max length: 337 cm TLHabitat: Tropical and subtropical oceans
4
Ocean sunfish (Mola mola)
The ocean sunfish is the best-known mola. It used to be credited with the 2,300 kg Kamogawa record, but that fish was re-identified as a giant sunfish. FishBase now gives Mola mola a maximum published weight of 1,300 kg and a length of 333 cm. The 2022 Azores study cites the heaviest ocean sunfish as 1,320 kg.
Scientific name: Mola molaFamily: Molidae (ocean sunfishes)FishBase max length: 333 cm TLHabitat: Temperate and tropical oceans
5
Kaluga (Huso dauricus)
The kaluga is the beluga's close relative in the Amur River basin. FishBase gives it a maximum published weight of 1.0 tonne and a maximum length of 560 cm, citing a 1962 reference. It lists the species as Critically Endangered (IUCN, assessed 2019). A 2025 revision moved the kaluga to the genus Sinosturio.
Scientific name: Huso dauricus (Sinosturio dauricus since 2025)Family: Acipenseridae (sturgeons)FishBase max length: 560 cm TLHabitat: Amur River basin
6
White sturgeon (Acipenser transmontanus)
The white sturgeon of western North America is the largest freshwater fish on the continent. FishBase gives a maximum published weight of 816 kg and a length of 610 cm, from a 1986 source, along with a maximum age of 104 years. The 816 kg figure is an estimate. The most authentic weighed record is about 630 kg.
Scientific name: Acipenser transmontanusFamily: Acipenseridae (sturgeons)FishBase max length: 610 cm TLHabitat: NE Pacific and rivers of western North America
7
Black marlin (Istiompax indica)
The black marlin is the heaviest billfish. FishBase gives a maximum published weight of 750 kg and a length of 465 cm (fork length). The heaviest fish actually weighed is the 707.61 kg IGFA all-tackle record, taken at Cabo Blanco, Peru, in 1953.
Scientific name: Istiompax indicaFamily: Istiophoridae (marlins)FishBase max length: 465 cm FLHabitat: Tropical and subtropical Indo-Pacific
8
Atlantic bluefin tuna (Thunnus thynnus)
The Atlantic bluefin is the largest tuna. FishBase gives a maximum published weight of 684 kg and a maximum length of 458 cm. The IGFA all-tackle record is a 678.58 kg fish taken off Aulds Cove, Nova Scotia, in 1979.
Scientific name: Thunnus thynnusFamily: Scombridae (tunas)FishBase max length: 458 cm TLHabitat: Atlantic Ocean and Mediterranean
9
Swordfish (Xiphias gladius)
The swordfish is the only living member of its family. FishBase gives a maximum published weight of 650 kg and a length of 455 cm (fork length). The IGFA all-tackle record is a 536 kg fish taken off Chile in 1953.
Scientific name: Xiphias gladiusFamily: Xiphiidae (swordfish)FishBase max length: 455 cm FLHabitat: Tropical and temperate oceans worldwide
10
Blue marlin (Makaira nigricans)
FishBase gives the blue marlin a maximum published weight of 636 kg and a length of 500 cm. That matches the 636 kg IGFA Atlantic blue marlin record, taken off Vitória, Brazil, in 1992. Some references, including Wikipedia, quote up to 818 kg, but FishBase's current entry does not.
Scientific name: Makaira nigricansFamily: Istiophoridae (marlins)FishBase max length: 500 cm TLHabitat: Tropical and temperate oceans
Full comparison
#
Name
Scientific name
Family
FishBase max length
Habitat
1
Beluga sturgeon (Huso huso)
Huso huso
Acipenseridae (sturgeons)
800 cm TL
Caspian and Black Sea basins (anadromous)
2
Giant sunfish (Mola alexandrini)
Mola alexandrini
Molidae (ocean sunfishes)
325 cm TL (Azores record fish)
Temperate and tropical oceans
3
Sharptail mola (Masturus lanceolatus)
Masturus lanceolatus
Molidae (ocean sunfishes)
337 cm TL
Tropical and subtropical oceans
4
Ocean sunfish (Mola mola)
Mola mola
Molidae (ocean sunfishes)
333 cm TL
Temperate and tropical oceans
5
Kaluga (Huso dauricus)
Huso dauricus (Sinosturio dauricus since 2025)
Acipenseridae (sturgeons)
560 cm TL
Amur River basin
6
White sturgeon (Acipenser transmontanus)
Acipenser transmontanus
Acipenseridae (sturgeons)
610 cm TL
NE Pacific and rivers of western North America
7
Black marlin (Istiompax indica)
Istiompax indica
Istiophoridae (marlins)
465 cm FL
Tropical and subtropical Indo-Pacific
8
Atlantic bluefin tuna (Thunnus thynnus)
Thunnus thynnus
Scombridae (tunas)
458 cm TL
Atlantic Ocean and Mediterranean
9
Swordfish (Xiphias gladius)
Xiphias gladius
Xiphiidae (swordfish)
455 cm FL
Tropical and temperate oceans worldwide
10
Blue marlin (Makaira nigricans)
Makaira nigricans
Istiophoridae (marlins)
500 cm TL
Tropical and temperate oceans
How we ranked this
Species are ranked by the maximum published weight (kg) in each species' FishBase summary page, heaviest first. FishBase compiles these figures from the literature and cites a reference for each. The one exception is the giant sunfish: its FishBase main page still shows 2,300 kg (the 1996 Kamogawa fish), but a newer weighed specimen, 2,744 kg from the Azores, was published in the Journal of Fish Biology in 2022 and is recognised by Guinness World Records. We use 2,744 kg because it is the same measure (a published maximum weight), just more recent. Only bony fish are included. Weights are for whole fish. Lengths in the table are FishBase maximum lengths, given as total length (TL) or fork length (FL) as FishBase reports them.
FAQ
What is the heaviest bony fish in the world?
It depends on the measure. The heaviest bony fish ever weighed and confirmed is a 2,744 kg giant sunfish (Mola alexandrini) found off the Azores in December 2021, and Guinness recognises it. On FishBase's maximum published weights, the beluga sturgeon ranks higher at 3,200 kg, but that figure rests on historical records. The largest beluga specimen most often accepted weighed 1,571 kg.
Was the ocean sunfish (Mola mola) ever the record holder?
For decades the record was a 2,300 kg fish caught off Kamogawa, Japan in 1996, credited to Mola mola. In 2017 researchers from Hiroshima University, the University of Tokyo and Murdoch University re-identified it as Mola alexandrini. FishBase now gives Mola mola a maximum of 1,300 kg.
Which species just missed the top 10?
In FishBase: the Chinese sturgeon (600 kg), the Atlantic goliath grouper (455 kg), the Pacific bluefin tuna (450 kg) and the giant grouper (400 kg). The hoodwinker sunfish (Mola tecta) is much smaller than its relatives, with a FishBase maximum of 211 kg.