Biggest
Freshwater Fish
GIANT MEKONG CATFISH
Pangasius gigas
Freshwater
Fish Records
It's official!
The new world record holder for the biggest freshwater fish is the
Giant Mekong catfish (Pangasius gigas).
The biggest one ever captured and measured was caught in Thailand
in May of 2005.
The fish in the photo below was
captured by some fisherman where the species is considered endangered,
but can still be caught with special permits. The fish was turned
in to the Department of Fisheries where the eggs and sperm are collected
from these rare giants and harvested for a captive breeding program
to keep the species alive.
This giant catfish caught in May of 2005 was 9 feet long and
weighed 646 lbs. This is more than 5 times bigger than the 'world
record' catfish caught in North America. |
This giant catfish inhabits the
waters of the Mekong River in China, which flows southward into Southeast
Asia. This fish is found as far south as Cambodia and Thailand where
it is known as Pla Buk, which means simply "huge fish".The
dimensions of these catfish are very impressive, with the largest
supposedly growing up to 10ft/3m and weighing up to 660lbs/300kg.
Scientists have recently discovered
someting amazing about the Giant Mekong catfish; they live out part
of their lives at sea. Most people have the impression of catfish
as slow, lumbering bottom-feeders, but it turns out that the migration
routes of these catfish rival those of the better known salmon. Scientists
have recorded Pangasius gigas traveling as much as 600 miles
(1000 km) inland from the south China sea up the Mekong River to spawn.
The waters of the Mekong River are
very murky and make it difficult to track the movements of the fish.
In order to determine where the Mekong catfish have been, scientists
examined chemical markers called isotopes in bone and muscle tissue of catfish from the Khone Falls region of
the Mekong. The team found evidence that the freshwater-dwelling fish
had migrated recently from a marine habitat. Although this method
of fish tracking is a highly regarded method, it appears that this
is the first time it has been used to track the migration routes of
river catfish species from a marine environment.
The recent discovery that Mekong
catfish are anadromous, (moving from coastal
waters into fresh waters to spawn) has surprised even scientist's
long-held notions of freshwater species. It may be that many other
species of catfish also have similar migration habits, and that other
species of freshwater fish may be found living part of their lives
at sea. It certainly gives new meaning to the concept of "freshwater
fish", if they spend part of their lives living in the salty
waters of a marine environment.
As big as the Giant Mekong catfish
can get, there are rumored to be other species of freshwater fish
whose dimensions rival those of the Mekong catfish. Among them are
the Arapaima and huge freshwater stingrays, both found living in the Amazon River. The giant
Chinese paddlefish is also a serious contender for world's biggest
freshwater fish, but very little is known about this species that
seems to be rapidly disappearing.
For more information about giant
freshwater fish species see the National Geographic sponsored Megafishes
Project, and meet the scientists
who travels the world looking for the world's biggest
freshwater fish.
