Mekong river catfish (oil pangasius) once topped the list of the largest freshwater fish, but today this position belongs to the Beluga sturgeon.
Sturgeons (Acipenseridae) are known as “living fossils” because they appeared on Earth more than 250 million years ago. Of the 27 species still extant at these properties, the Beluga sturgeon (Huso huso) is the largest representative.
In 1827, a Beluga sturgeon caught at the mouth of the Volga River grew up to 7.2 m in length and weighed 1,571 kg, which is equivalent to a full-grown whitefish. It is the largest specimen ever recorded to date.
According to the International Union for Conservation of Nature (IUCN), Beluga sturgeon can live for more than 100 years in the wild. When grown to their maximum size, they become table predators, feeding mainly on large fish such as carp and salmon. These shoes when hunting mollusks, aquatic birds, harpoons and other vision fishes.
Their long lifespan and active hunting properties are two of the reasons why the Beluga sturgeon can grow to such a large size, says expert Phaedra Doukakis from the National Oceanic and Gas Administration in the United States. (NOAA) said with Live Science.
However, today most sturgeon cannot exceed 3.5 m in length. This is due to pressure from overfishing, which has made large and aged individuals increasingly strange in recent decades. River sturgeon), Beluga sturgeon as an adult spends a lot of time living in saltwater and freshwater environments. That is why we were not previously recognized as the largest freshwater fish in the world. This title once belonged to the oilfish (Pangasianodon gigas), a “pure freshwater” fish from Southeast Asia. They can grow to more than 3 m in length and weigh 150 – 350 kg.
Both of these fish groups are considered “critically endangered” in the IUCN Red List. Besides the threat of attack from overfishing, the construction of river vandals also disrupts their habitat and breeding.