We tend to think that in the seas and oceans there are huge creatures, but that in a river or in a lake it is difficult to find mammoth fish.
However, the Yangtze paddlefish (Psephurus gladius) is one of the largest fish: three meters in length and 300 kg in weight.
However, in January 2020, the Chinese Academy of Fisheries Sciences and experts from the International Union for Conservation of Nature formally declared it extinct .
It is likely to disappear between 2005 and 2010 due to overfishing and habitat loss.

Other criteria
There are several species that aspire to the title of largest water fish, depending on the criteria we use. The arapaima (Arapaima gigas) of the Amazon basin, in South America, can measure up to 4.5 meters long and reach 200 kg.

The Mekong giant catfish and the Indochinese Thai shark weigh around 300 kg, but do not exceed 3 meters in length.