Big Freshwater Fish: The Largest Species by Weight

Ranked by the heaviest weight a named source gives, counting only fish that live their whole lives in fresh water:

• Giant freshwater stingray (Southeast Asia): 300 kg (661 lb), the 2022 Cambodian fish (Mongabay; Wikipedia). See our freshwater stingray page.
• Mekong giant catfish (Mekong): up to 350 kg (770 lb) reported; the 2005 record fish weighed 293 kg (Wikipedia).
• Short-tailed river stingray (South America): 1.5 to 1.6 m across and up to 220 kg (490 lb) (Wikipedia).
• Nile perch (Africa): 2 m and 200 kg (440 lb) (Wikipedia list of largest fish).
• Arapaima (Amazon): about 10 ft and over 400 lb (Boundless Pursuit); see our arapaima page.
• Alligator gar (North America): 148.5 kg (327 lb) and 2.6 m (8.5 ft), a verified 2011 fish (Wikipedia list); see our alligator gar page.
• Wels catfish (Europe): heaviest authenticated 134.97 kg (297.6 lb), river Po, 2010 (Wikipedia).
• Murray cod (Australia): 113 kg (249 lb) and 1.83 m (Wikipedia list).
• Siberian taimen (Asia): 105 kg (231 lb) and 2.1 m (Wikipedia list).
• American paddlefish (North America): largest recorded over 7 ft and about 198 lb (Wikipedia).

Just outside the ten, the blue catfish reaches 143 lb; that fish came from Kerr Lake on the Virginia-North Carolina line in June 2011 (Wikipedia).

The giant freshwater stingray. The 2022 fish from Stung Treng province, Cambodia, weighed 300 kg (661 lb) and measured about 4 m (13 ft) from snout to tail; researchers with the Wonders of the Mekong project tagged it and put it back (Mongabay). It beat the 293 kg Mekong giant catfish caught in Thailand in 2005.

The answer changes if you count sturgeon, which spend part of their lives at sea. The beluga sturgeon is listed at 7.2 m and 2,072 kg (4,570 lb), and the kaluga at 5.6 m and 1,140 kg, but both are anadromous rather than strictly freshwater (Wikipedia list of largest fish). That is why "biggest freshwater fish" lists disagree.

MeatEater (July 2025) ranks North America's five biggest as white sturgeon (up to 20 ft and more than 1,200 lb), alligator gar (up to 10 ft and more than 300 lb), paddlefish (more than 7 ft, upwards of 150 lb), blue catfish (more than 5 ft, over 100 lb) and king (Chinook) salmon (more than 5 ft, up to about 100 lb). Wikipedia's list is more cautious about the white sturgeon: 500 kg (1,100 lb) and 4 m verified, with 907 kg (2,000 lb) and 6.1 m unverified. Sturgeon and salmon both use the sea, so among fish that never leave fresh water, the alligator gar is the heaviest in North America.

Across all fish, fresh and salt water, the biggest is the whale shark, which NOAA Fisheries says grows to more than 50 ft and may weigh several tons. The largest fish are sharks and rays of the open sea; the heaviest freshwater species above would not come close. For fish that live only in fresh water, the top five by weight are the giant freshwater stingray, Mekong giant catfish, short-tailed river stingray, Nile perch and arapaima.

That figure is attached to the platinum form of the Asian arowana, an aquarium fish, not a giant. Many list sites repeat it, but the largest price we could trace to a named report is $300,000 for an albino arowana, which The Hustle (1 October 2024) says was "purportedly" sold by a Malaysian breeder. Our Asian arowana page explains prices and why the fish is banned in the US.

Many of the biggest freshwater fish are also the most threatened, which top-10 lists rarely mention:

• Chinese paddlefish: once recorded at over 3.6 m (12 ft); the IUCN formally listed it as extinct in July 2022. The last confirmed fish was caught on 24 January 2003 at Yibin, Sichuan (Wikipedia).
• Mekong giant catfish: Critically Endangered; catch data suggest an 80% fall over 14 years, and it now survives only in small, isolated groups in the middle Mekong (Wikipedia).
• Giant freshwater stingray: Endangered; estimated 30 to 50% declines over 20 to 30 years in central Thailand and Cambodia (Wikipedia).
• American paddlefish: Vulnerable on the IUCN Red List; its roe is sold as caviar, which drives poaching (Wikipedia).

If you catch a giant, a clear photo and a quick release help the fish and give researchers a record. See our guide to handling and releasing fish.

Research and drafting for this page were assisted by AI and checked line by line against the sources listed below. Every number names the organisation it comes from, and where sources disagree we say so instead of picking one silently. Prices carry the date we checked them (25 September 2026); they change, so confirm before you rely on them. If you find an error, tell us and we will correct it.