Top 12 Giant Fish Species Facing Extinction Risks

Catfish come in many varieties, and the Yellow Catfish is one species that is also facing extinction. Found in the Paraná River in Argentina, these fish can grow up to 1.4 meters in length and weigh up to 50 kg. They inhabit the riverbed and hunt small fish at night. The Yellow Catfish (Scientific Name: Ameiurus natalis; 'natalis' in Latin means 'having a large bottom') is a member of the North American Ictaluridae family, found throughout North America, particularly in the United States, ranging from central Texas to North Dakota, and eastward across the Great Lakes to the East Coast. In Minnesota, they can be found in the eastern and central parts of the state. Though considered a small sport fish, they are also tolerant of polluted environments. These catfish thrive in bottom areas with muddy, rocky, sandy, or clay-like grounds. They are found in river pools and sluggish sections of rivers, as well as in lakes and ponds, where the water can range from slow-moving and low-oxygen to faster-flowing, clean, and clear water with aquatic plants. Fishermen commonly find them in slow-moving streams and rivers with gravel bottoms.

Found in rivers across Colombia, Venezuela, Ecuador, Peru, Bolivia, and Brazil, the Red-tailed Catfish has a white belly, small spots on its back, and a striking red tail. This species is a favorite among sport fishermen, with the world record held by Brazilian angler Gilberto Fernandes. He caught a fish weighing 56 kg. The Red-tailed Catfish is also hunted in its juvenile state for the ornamental pet trade. It can grow up to 65 kg, and it is currently in urgent need of protection to avoid the risk of extinction.

White Sturgeon is a massive fish species, it can reach up to 450 kg and 4.5 meters in length. One of the largest fish species in North America, it is found in the Fraser River (Canada) and the Sacramento River in California (USA). This silvery fish is currently facing a dramatic decline in numbers, primarily due to human activities like dam construction. Dams are the main threat to this species, as they divide river systems, resulting in reduced food supply and disrupted habitats for the White Sturgeon. Many of these sturgeons, which previously swam upstream to avoid saltwater intrusion, are now trapped by the dams blocking their migration.

The world’s largest freshwater fish, also critically endangered and facing extinction, is the Kaluga Sturgeon. Known for its immense size, it can grow up to 5-6 meters long and weigh around 400 kg. Some individuals even reach a weight of up to one ton when fully grown. The Kaluga is hunted primarily for its eggs, contributing to its rapid decline.

Paddlefish is another large fish species related to sturgeons, found in the Missouri River in Montana (USA), with individuals reaching up to 1.8 meters and weighing as much as 90 kg. Human activities, such as dam construction, have disrupted the natural migration and spawning routes of this species, causing their population to be severely threatened.

Paddlefish, also known as American Paddlefish, Polyodon spathula or Mississippi Paddlefish, is a species of paddlefish inhabiting the slow-moving waters of the Mississippi River Basin. Its unique appearance features a long, flat snout extending forward. It is believed to have gone extinct in Lake Erie and its tributaries. This large freshwater fish can grow up to 220 cm in length and weigh up to 100 kg. The name “paddlefish” comes from its distinctive paddle-like snout. It is thought that this species uses its sensitive electroreceptive snout to detect prey and navigate while migrating to spawning grounds. They mainly feed on zooplankton, but also consume crustaceans and bivalves.

This species of catfish can be found in the Uttarakhand region of India, where it grows to an enormous size with sharp teeth and long whiskers. It is believed that this fish was responsible for a series of attacks on swimmers in the Kali River in India between 1998 and 2007. Unfortunately, its population has drastically decreased. The size of a Goonch catfish can reach up to 2 meters and weigh 90 kg. This massive predator has been implicated in attacks on swimmers in the Kali River during the late 1990s and early 2000s. The Goonch catfish, with its red tail, found in the Rewa River, Guyana, can grow up to 45 kg in weight.

Goonch is a large, carnivorous catfish that thrives in fast-flowing rivers across Asia, particularly in the steep rapids of rivers originating from the Himalayas and the upper stretches of the Mekong River. Despite being strong and aggressive, the species is now facing significant population decline due to increasing pollution in these rivers.

Potamotrygon motoro, also known as the Ocellate River Stingray, is a freshwater stingray species in the family Potamotrygonidae. It was the first species described in this family and remains the most common, found throughout the Río de la Plata, Amazon, Mearim, and Orinoco basins in the tropical and subtropical regions of South America. It is sometimes kept in aquariums. The ray has a flattened, round body with a short, strong tail. Its dorsal surface is yellow-brown to dark yellow, decorated with yellow spots outlined in black. This species also comes in other colors such as orange, marble, black, and green, with various spot patterns. Potamotrygon motoro inhabits the Paraná River in Argentina, Brazil, Paraguay, Uruguay, Venezuela, and tributaries of the Amazon River. Potamotrygon motoro can weigh up to 15 kg.

Currently, overfishing, dam construction, and environmental pollution are significantly reducing the population of this species. The giant Potamotrygon motoro stingrays in the Paraná River of Argentina can grow up to one meter in length and weigh 15 kg. According to arkive.org, these rays are widely distributed and found in rivers across Argentina, Brazil, Paraguay, Uruguay, Venezuela, and the Amazon basin. The construction of hydroelectric dams and environmental pollution are the main threats to this species.

Wallago Catfish is a carnivorous species, known for its large, gray body, slightly arched back, and a wide jaw for hunting prey underwater. They are found across rivers from Pakistan to Vietnam, and as adults, they can grow up to 2 meters in length. In India, illegal fishing practices are threatening the survival of this species, pushing it towards extinction.

Tapah Catfish (Scientific name: Wallago leerii) is a type of catfish belonging to the Siluridae family, within the order Siluriformes, native to Southeast Asia. This species can grow up to 2 meters (6 feet 7 inches) long and weigh up to 95 kg (209 lbs). The indigenous people have used it as a food source for centuries. In Malaysia, the giant Tapah catfish can weigh up to 100 kg and is notoriously hard to catch. The local people refer to it as a mystical fish. While Tapah is still common in large lakes and rivers, especially in Malaysia, where it typically weighs between 1 to 3 kg, the giant Tapah is now extremely rare. Due to pollution and overfishing, this once abundant species is now near extinction.

With a body length of 3 meters and weighing over 180 kg, Arapaima (also known as the Arapaima gigas) is one of the largest freshwater fish species in the world and the largest fish in the Amazon River, as well as in South America. Often referred to as the 'Amazon River monster' due to its immense size, the Arapaima is now facing a dramatic decline in numbers. This is mainly caused by excessive fishing and its economic and food value. As a result, the species is now under threat of extinction.
Arapaima can reach lengths greater than 2 meters (6.6 feet), with some individuals growing over 2.5 meters (8.2 feet) long and weighing up to 100 kg (220 lbs). The largest recorded Arapaima weighed around 200 kg. This fish is highly sought after in South America, where it is commonly caught using nets for export and with harpoons for local consumption. Because of this, finding Arapaimas longer than 2 meters in the wild has become an extremely rare occurrence.

The Giant Freshwater Stingray is a large, predatory species of ray found predominantly in the rivers of Asia, especially in the Mekong River basin and the Himalayan foothills. These creatures are considered endangered due to severe environmental pollution and overfishing.

The Giant Stingray is also part of local legends and rumors, with some people claiming that these rays are responsible for consuming human corpses that are cast into the river. However, no evidence has ever been presented to support these stories. Moreover, due to the rampant fishing of this species, very few rays reach the size necessary to consume large prey like humans.

The Vampire Fish (scientific name: Hydrolycus scomberoides) is a predatory freshwater fish found in the Amazon River basin, with the eastern boundary of its range marked by the Tapajós River. It was the first species described within the Hydrolycus genus. The Vampire Fish is famous for its sharp teeth, particularly the two long and pointed fangs in its lower jaw. This is why the species has earned its dramatic name. The fish can grow up to 1.17 meters in length and weigh as much as 17.8 kg.

Many people often mistake this fish for a smaller species due to the presence of other vampire-like fish. The Vampire Fish is an extremely aggressive predator and has earned the title of the most ferocious freshwater fish in the world. Unfortunately, its population is rapidly declining due to habitat loss and overfishing. The Vampire Fish and the giant fish species in the Mekong River are among the largest fish species globally, now endangered due to dam construction and overfishing.

The Freshwater Stingray inhabits the river systems of Thailand, Borneo, New Guinea, and northern Australia. These massive creatures can reach up to 5 meters in length and weigh as much as 600 kg. The construction of dams and human overfishing are threatening their natural habitats, placing them at risk of extinction. The species is classified as vulnerable by the International Union for Conservation of Nature (IUCN). "Over 70% of the world's giant freshwater fish species (including the giant freshwater stingray) are at risk of extinction. Our urgent task is to study and protect them from threats such as dam building and excessive fishing," said Mr. Hogan.

The Giant Freshwater Stingray is currently threatened by dam construction, fishing, and water pollution. As one of the largest freshwater fish in the world, there is still very little information available about the species. No one knows how many giant freshwater stingrays remain in the world, or even what their preferred habitat is. These creatures are believed to have existed millions of years ago with little change since then, and they are typically buried in the riverbeds of sand or mud.

A fish species with impressive size, admired by other fish, is the Giant Mekong Catfish. As the name suggests, it lives in the legendary Mekong River, and it has a large, flat head, a wide mouth with long barbels on the upper jaw, a small dorsal fin, and abdominal fins that extend to the tail. Fully grown Giant Mekong Catfish can reach 3 meters in length and weigh up to 300 kg. In the lower reaches of the Mekong River, particularly in Laos, Vietnam, Cambodia, and Thailand, the population of this species has been declining significantly. The Giant Mekong Catfish is listed in the Vietnam Red Book and the IUCN Red List.

"Large dams are having devastating effects on the river ecosystems. For example, the Giant Mekong Catfish, which grows to the size of a North American grizzly bear, is threatened by a series of dams being built downstream; these dams block the migration routes to their spawning grounds, increasing the risk of extinction," said Mr. Hogan, a researcher with 20 years of experience studying the species.