The Cambodia giant catfish is perhaps the most interesting and most
threatened species in the Mekong River. For this reason, conservationists have
chosen it as a sort of "flagship" species to promote conservation on
the Mekong.
With recorded sizes of up to 10.5 ft (3.2 m) and 660 lb (300 kg), the Mekong
giant catfish currently holds the
Guinness Book of World Records'
position for the world's largest freshwater fish.
Although research projects are currently ongoing, relatively little is known
about this species. Historically, the fish's natural range reached from the
lower Mekong in Vietnam (above the tidally influenced brackish water of the
river's delta) all the way to the northern reaches of the river in the Yunnan
province of China, spanning almost the entire 4,800-km length of the river.
Due to threats, this species no longer inhabits the majority of its original; it is
now believed to only exist in small, isolated populations in the middle Mekong
region.
Fish congregate during the beginning of the rainy season and migrate upstream
to spawn.
They live primarily in the main channel of the river, where the water depth is
over 10 m,
while researchers, fishermen and officials have found this species in the
Tonle Sap
River and Lake in Cambodia, a UNESCO Biosphere reserve. In the past, fishermen
have reported the fish in a number of the Mekong's tributaries; today, however, essentially no sightings are reported outside of the main Mekong river
channel and the Tonle Sap region.
In infancy, this species feeds on zooplankton in the river and is known to
be cannibalistic.
After approximately one year, the fish becomes herbivorous, feeding on
filamentous algae, probably ingesting larvae and periphyton accidentally.The fish likely obtains its food from algae growing on submerged rocky
surfaces, as it does not have any sort of dentition.
Endemic to the lower half of the Mekong river, this catfish is in danger of
extinction due to overfishing, as well as the decrease in water quality due to
development and upstream damming by the
People's Republic of China. The current
IUCN
Red List for fishes classes the species as Critically Endangered; the
number living in the wild is unknown, but catch data indicate the population
has fallen by 80% in the last 14 years.
It is also listed in Appendix I of
CITES, banning international trade.
In
The Anthropologists' Cookbook (1977), Jessica Kuper noted the
importance of the
pa beuk to the Lao people and remarked, "In times
gone by, this huge fish, which is found only in the Mekong, was fairly
plentiful; but in the last few years the number taken annually has dwindled to
forty, thirty or twenty, and perhaps in 1976 even fewer. This is sad, as it is
a noble fish and a mysterious one, revered by the Lao."
Fishing for the Mekong giant catfish is illegal in the wild in Thailand,
Laos, and
Cambodia, but
the bans appear to be ineffective, and the fish continue to be caught in all
three countries.
[1]
However, in recognition of the threat to the species, nearly 60 Thai fishermen
agreed to stop catching the endangered catfish in June 2006, to mark the 60th
anniversary of
Bhumibol Adulyadej's ascension to the throne of
Thailand.
Thailand is the only country to allow fishing for private stocks of Mekong
giant catfish. This helps save the species, as lakes purchase the small fry
from the government breeding program, generating extra income that allows the
breeding program to function. Fishing lakes, such as Bung Sam Ran in Bangkok,
have the species up to 140 kg. The most common size landed is 18 kg,
although some companies specialise in landing the larger fish.
