Jul 16, 2006
Deutsche Presse-Agentur
Bangkok - Thailand's fisheries department has tagged 19 giant catfish with micro chips and released them in the Mekong River in an attempt to unravel the mysteries of the endangered species, media reports said on Sunday.
While Thailand has been successfully artifically breeding the giant catfish - the world's second largest fresh water fish that can grow up three metres in length - for two-and-a-half decades, there has been less progress in mapping the species' migratory and breeding behavior in its natural environment, the Mekong River that meanders through China, Laos, Myanmar (Burma), Thailand, Cambodia and Vietnam.
A new program initiated by the Mekong Wetland Biodiversity Program of the Thai Fisheries Department, is attempting to better understand the gentle giant of the Mekong by mapping its behavior with micro chips, said The Nation newspaper.
So far, 19 of giant catfish - 18 of them raised in captivity and one from the wild - have been tagged and released into the Mekong.
'The latest data showed that most of the tagged fish are heading downstream following their release. Only the wild tagged fish has made significant (more than 30 kilometres) upstream movement,' said Zeb Hogan, the program's conservation-group scientist.
The giant catfish is known to migrate upstream to spawn in the northernmost regions of the Mekong in Laos and China. In the past the fish was most populous in the Tongle Sap Lake of Cambodia.
Since 1980 the Thai Fisheries Department has allowed fishermen in Ban Hat Krrai village of Chiang Rai province to catch the giant mekong once a year on its migratory journey upstream, in order to use its eggs for artificial breeding in Thai lakes and ponds.
Recent advances in its breeding program have resulted it the fish producing offspring without artificial insemination and now scientists are working on improving the genetic diversity of the offspring by matching fish bred in captivity will wild ones.
'The problem with artificial breeding is mating between cousins, scientifically called in-breeding, which would make the gene weaker in later generations,' Uthairat Na Nakorn, a scientist from Thailand's Kasetsart University, told The Nation.
Improved breeding methods have assured that the species will not go extinct but environmentalists insist the fish still required protection in the Mekong, where it has all but disappeared.
The Fisheries Department this year for the first time prohibited the annual catch of giant mekong in Chiang Rai, after the yearly haul dropped off dramatically to only one in 2003, down from 69 in 1990.
The giant catfish, known as 'pla beuk' in Thai, has been put in the red list of critically endangered species by the World Conservation Union. Pla beuk meat is considered a local delicacy.
While Thailand has been successfully artifically breeding the giant catfish - the world's second largest fresh water fish that can grow up three metres in length - for two-and-a-half decades, there has been less progress in mapping the species' migratory and breeding behavior in its natural environment, the Mekong River that meanders through China, Laos, Myanmar (Burma), Thailand, Cambodia and Vietnam.
A new program initiated by the Mekong Wetland Biodiversity Program of the Thai Fisheries Department, is attempting to better understand the gentle giant of the Mekong by mapping its behavior with micro chips, said The Nation newspaper.
So far, 19 of giant catfish - 18 of them raised in captivity and one from the wild - have been tagged and released into the Mekong.
'The latest data showed that most of the tagged fish are heading downstream following their release. Only the wild tagged fish has made significant (more than 30 kilometres) upstream movement,' said Zeb Hogan, the program's conservation-group scientist.
The giant catfish is known to migrate upstream to spawn in the northernmost regions of the Mekong in Laos and China. In the past the fish was most populous in the Tongle Sap Lake of Cambodia.
Since 1980 the Thai Fisheries Department has allowed fishermen in Ban Hat Krrai village of Chiang Rai province to catch the giant mekong once a year on its migratory journey upstream, in order to use its eggs for artificial breeding in Thai lakes and ponds.
Recent advances in its breeding program have resulted it the fish producing offspring without artificial insemination and now scientists are working on improving the genetic diversity of the offspring by matching fish bred in captivity will wild ones.
'The problem with artificial breeding is mating between cousins, scientifically called in-breeding, which would make the gene weaker in later generations,' Uthairat Na Nakorn, a scientist from Thailand's Kasetsart University, told The Nation.
Improved breeding methods have assured that the species will not go extinct but environmentalists insist the fish still required protection in the Mekong, where it has all but disappeared.
The Fisheries Department this year for the first time prohibited the annual catch of giant mekong in Chiang Rai, after the yearly haul dropped off dramatically to only one in 2003, down from 69 in 1990.
The giant catfish, known as 'pla beuk' in Thai, has been put in the red list of critically endangered species by the World Conservation Union. Pla beuk meat is considered a local delicacy.
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