Giant smooth tongue fish and divers a diver plays with an adult giant smooth tongue fish in the same aquarium at Manaus aquarium in Brazil. This South American giant is one of the largest freshwater fish in the world. It is called "pirarucu" in Brazil and "Paiche" in Peru. Some fish are more than 3 meters long and weigh up to 180 kg.
Because of overfishing, this kind of giant fish has become increasingly rare around the world. Several conservation programs in South America, including fishing bans and quotas, focus on the giant tongue fish.
Chinese sturgeon
A pair of Chinese sturgeons swim in an aquarium in Beijing, China. This freshwater giant weighs up to half a ton and is up to 5 meters long. It is the largest sturgeon on the earth. Chinese sturgeon has been listed as an endangered species due to China's river damming operations.
Giant Spanish mackerel
A boy poses next to a giant Spanish mackerel on the Tonle Sap river near Cambodia. The fish was taken ashore by local fishermen, tagged and released as part of a study of large freshwater species in the Mekong basin. There is evidence that the giant Spanish mackerel used to be 3 meters long and 300 kg in weight, but now, even if it is less than half of that, it is extremely rare.
Giant yellow Shaoxing fish
Fish experts believe that giant yellowfish, such as the one caught in the Mekong River in Cambodia, are the largest freshwater species on earth. The fish is more than four meters long.
Giant catfish
The Mekong giant catfish, such as the one on the fisherman's boat, is one of the largest in the world, with a length of up to 3 meters and a weight of up to 300 kg. Overfishing, dam construction and habitat destruction have seriously damaged this critically endangered species.