Uploaded December 2022 | Updated September 2026, 2 weeks ago
Beluga
The beluga is a species of sturgeon that inhabits portions of the Black Sea and the Caspian Sea. Because they continue to grow throughout their lifetime (which can be 100 years), the beluga might be the world's largest freshwater fish.1 Some of the largest belugas discovered have been nearly 24 feet long and weigh more than 3,500 pounds—numbers that also put them in contention for being the largest bony fish in the world by mass.
The beluga hatches its eggs in freshwater rivers, then lives its adult life in saltwater, returning upriver to spawn. Females do not reach maturity until 15 years of age. The beluga is also critically endangered, with a decreasing population.2
Mekong Giant Catfish
Many species of catfish can grow to mammoth sizes, but none compare to the Mekong giant catfish of Southeast Asia. Capable of growing up to 10 feet long and weighing more than 650 pounds, their size makes them a prized catch, and these giant catfish have been fished to near extinction.3 They have a remarkably fast growth rate, reaching 440 pounds in six years—and living up to 60 years.
Though they are now protected by national legislation in Thailand and Laos, they are likely to remain critically endangered due to the construction of upstream dams on the Mekong River.4
Alligator Gar
Due to a dual row of large teeth and a snout like an alligator, these carnivorous fish are able to live in fresh and saltwater. Measuring as long as 10 feet and weighing as much as 350 pounds, alligator gars are the second largest fish in North America.5
They live up to 50 years and have few natural predators. Found in the lower Mississippi River basin and in the waters of the Gulf Coast states, these fish tend to swim near the surface or among reeds where they can stalk and ambush prey, which they consume dead or alive.
Giant Freshwater Stingray
One of the largest freshwater species in the world, the giant stingray was first identified by scientists in the 1990s.8 These freshwater fish can grow to massive sizes, with some weighing in excess of 1,300 pounds and measuring nearly 15 feet across—half the length of a bus.9 They've been known to pull boats up and down rivers, and even down into the water.
Found in the rivers of Southeast Asia, they have tails that measure up to 15 inches long with a serrated spike that is capable of piercing bone and injecting venom. Unfortunately, the giant freshwater stingray is endangered due to fishing and habitat loss.10
Paddlefish
There are two extant species of paddlefish, one Chinese and the other American. They usually range from five to seven feet in length and weigh in around 60 pounds. The Chinese paddlefish—the larger of the two species, sometimes measuring as long as 10 feet—is critically endangered and believed to be possibly extinct.
Inhabiting the Yangtze River, these fish are mostly threatened by overharvesting and habitat loss. American paddlefish, which are listed as vulnerable, once inhabited the Great Lakes in Canada but now exclusively live in the Mississippi River basin.1112 They can grow to lengths of eight feet and weigh up to 150 pounds, living for 30 years in the wild.
Easily recognizable by their paddle-shaped snouts, these river giants are harmless filter-feeders, opening their mouths only to capture zooplankton.
Giant Barb
Carp of all varieties can grow to formidable sizes, but none are as large as the giant barb, aka King of Fish, found in Southeast Asia. This species of carp regularly grows to 10 feet in length; adults are rarely found under five feet.13
Although they grow to such large sizes, giant barbs are harmless. They prefer to eat small organisms like algae, phytoplankton, and occasionally fruit. The giant barb is critically endangered due to overfishing and habitat loss.
White Sturgeon
Easily the largest freshwater fish in North America, the white sturgeon can grow to 12 to 20 feet in length and can weigh nearly one ton.1 It's an ancient fish whose appearance has not changed in 175 million years. Found along the West Coast of North America, and as far north as the Aleutian Islands, white sturgeon inhabit rivers, streams, estuaries, and the sea.
They migrate upriver to spawn and have a lifespan of 80 to 100 years.15 Due to their size, white sturgeon are a popular target for fishermen, and while not federally listed, they are categorized as a state Species of Special Concern in California.16
#largestfreshwaterfish #largestfish #fish #freshwaterfish
Beluga
The beluga is a species of sturgeon that inhabits portions of the Black Sea and the Caspian Sea. Because they continue to grow throughout their lifetime (which can be 100 years), the beluga might be the world's largest freshwater fish.1 Some of the largest belugas discovered have been nearly 24 feet long and weigh more than 3,500 pounds—numbers that also put them in contention for being the largest bony fish in the world by mass.
The beluga hatches its eggs in freshwater rivers, then lives its adult life in saltwater, returning upriver to spawn. Females do not reach maturity until 15 years of age. The beluga is also critically endangered, with a decreasing population.2
Mekong Giant Catfish
Many species of catfish can grow to mammoth sizes, but none compare to the Mekong giant catfish of Southeast Asia. Capable of growing up to 10 feet long and weighing more than 650 pounds, their size makes them a prized catch, and these giant catfish have been fished to near extinction.3 They have a remarkably fast growth rate, reaching 440 pounds in six years—and living up to 60 years.
Though they are now protected by national legislation in Thailand and Laos, they are likely to remain critically endangered due to the construction of upstream dams on the Mekong River.4
Alligator Gar
Due to a dual row of large teeth and a snout like an alligator, these carnivorous fish are able to live in fresh and saltwater. Measuring as long as 10 feet and weighing as much as 350 pounds, alligator gars are the second largest fish in North America.5
They live up to 50 years and have few natural predators. Found in the lower Mississippi River basin and in the waters of the Gulf Coast states, these fish tend to swim near the surface or among reeds where they can stalk and ambush prey, which they consume dead or alive.
Giant Freshwater Stingray
One of the largest freshwater species in the world, the giant stingray was first identified by scientists in the 1990s.8 These freshwater fish can grow to massive sizes, with some weighing in excess of 1,300 pounds and measuring nearly 15 feet across—half the length of a bus.9 They've been known to pull boats up and down rivers, and even down into the water.
Found in the rivers of Southeast Asia, they have tails that measure up to 15 inches long with a serrated spike that is capable of piercing bone and injecting venom. Unfortunately, the giant freshwater stingray is endangered due to fishing and habitat loss.10
Paddlefish
There are two extant species of paddlefish, one Chinese and the other American. They usually range from five to seven feet in length and weigh in around 60 pounds. The Chinese paddlefish—the larger of the two species, sometimes measuring as long as 10 feet—is critically endangered and believed to be possibly extinct.
Inhabiting the Yangtze River, these fish are mostly threatened by overharvesting and habitat loss. American paddlefish, which are listed as vulnerable, once inhabited the Great Lakes in Canada but now exclusively live in the Mississippi River basin.1112 They can grow to lengths of eight feet and weigh up to 150 pounds, living for 30 years in the wild.
Easily recognizable by their paddle-shaped snouts, these river giants are harmless filter-feeders, opening their mouths only to capture zooplankton.
Giant Barb
Carp of all varieties can grow to formidable sizes, but none are as large as the giant barb, aka King of Fish, found in Southeast Asia. This species of carp regularly grows to 10 feet in length; adults are rarely found under five feet.13
Although they grow to such large sizes, giant barbs are harmless. They prefer to eat small organisms like algae, phytoplankton, and occasionally fruit. The giant barb is critically endangered due to overfishing and habitat loss.
White Sturgeon
Easily the largest freshwater fish in North America, the white sturgeon can grow to 12 to 20 feet in length and can weigh nearly one ton.1 It's an ancient fish whose appearance has not changed in 175 million years. Found along the West Coast of North America, and as far north as the Aleutian Islands, white sturgeon inhabit rivers, streams, estuaries, and the sea.
They migrate upriver to spawn and have a lifespan of 80 to 100 years.15 Due to their size, white sturgeon are a popular target for fishermen, and while not federally listed, they are categorized as a state Species of Special Concern in California.16
#largestfreshwaterfish #largestfish #fish #freshwaterfish
