- Kingdom: Animalia
- Phylum: Chordata
- Class: Actinopterygii
- Order: Siluriformes
- Family: Pangasiidae
- Genus: Pangasianodon
- Species: Pangasianodon gigas
The Giant Mekong catfish is one of the biggest fish in the world. A member of the shark catfish family which reaches enormous proportions. This native Thai fish species is currently recognized by the Guinness book of records as the Largest freshwater fish species on earth.
The Giant Mekong Catfish is the biggest catfish of the very widespread catfish species and also the largest freshwater fish ever recorded. In its native only to the Mekong river that runs through China, Laos, Thailand, Cambodia and Vietnam. This Giant catfish feeds almost exclusively on vegetation but in captivity will take other food items such as bread and ground bait mix.
Grey to white in colour and lacking stripes the Giant Mekong Catfish has no scales and is distinguished from other large catfish in its native habitat by its complete lack of teeth. Pangasianodon gigas is also the only catfish to be without barbels in adulthood, ( Juveniles are known to have small barbels as well as small teeth which gradually disappear as they reach maturity) this is strange as the long whiskers of most catfish are where the name "Catfish" comes from.
It is thought that juveniles have small teeth and barbels because their diet is not only vegetarian, they have been known to feed on insects, snails or small crabs, this in itself would account for the barbels which are used to locate food on the muddy bed of its habitat and the small teeth needed to crush hard shells and bodies of these small invertebrates.
The King of fish grows rapidly (the fastest growth rate of any freshwater fish) and can reach a weight of 150 - 200 KG (330lb - 440lb) in only six years. As it grows and becomes more mature its Barbels slowly disappear along with the small teeth and it becomes almost completely vegetarian feeding on periphyton, zoobenthos, benthic algae, aquatic weeds and terrestrial plants that enter the river in times of flood.
The Giant Mekong catfish which is endemic to the lower half of the Mekong river is now in extreme danger of extinction due to overfishing, water pollution (higher levels of silt and mud are being deposited into the Mekong river from large building projects upstream, this silt eventually leads to less oxygen in the water which in turn suffocates plant life which is the natural food for the Giant Mekong catfish) and blocking of its spawning routes by damming projects in the higher reaches of the Mekong river in China.
Unfortunately, due to extreme pressure from all angles the Giant Mekong catfish is now classed on the ICUN red list for fishes as Critically Endangered.
The number of fish living in the wild is not known, but catch data collected from local fishermen indicate that the population has fallen dramatically, by as much as 80 percent in the last decade.