The giant catfish is uncommon yet broadly presented through the Mekong Basin. Mature fish seem to be found in major channels of the Mekong River and its tributaries. Juvenile fish seem to stick around wetland areas of the Mekong Basin. In the dry season mature fish migrate vast distances up river and start spawning when the rains arrive. The eggs and hatchlings are being transported downstream where juveniles may scatter into floodplains and other wetland zones. Not much information is known about the habitat of juvenile giant catfishes as they are very rare to be found.
Genetic analyses have shown the possibility of two individual spawning grounds located in Northern Thailand and in Cambodia but further investigation is needed for …show more content…
Three scenarios of predicted spawner population
Scenario 1: a complete stop in fishing result in a quick recovery in population.
Scenario 2: Fishing continues is a traditional way, resulting in fluctuations in populations over the next 30 years but population can recover.
Scenario 3: Reproduction fails because of natural factors or habitat degradation (construction of hydro dams) which results in a decline in population towards extinction.
There is currently a substantial amount of captive giant catfishes with estimated around 20.000 mature individuals. The captive population requires management in genetic diversity and attention towards the rate of domestication. At the present these captive fishes have a large genetic diversity to effective conserve the species and could be released back in nature.
At the present the giant catfish is listed on the IUCN list as critically endangered. This classification was justified in 1990s based on the criteria: population numbers are less than 50 mature individuals. Since that time the numbers have recovered to some …show more content…
Dam constructions reduce the flow nutrients in sediment loads. Dams change the flow of river and alter the speed and timing of seasonal floods. Change in the temperature of water. Blocks fish migrations. Change in water quality that can alter spawning behaviour for fish.
Changes near spawning habitats have in potential the most impact.
Electric hydro dams
Map of hydrodams on Mekong.
Solutions to the problems:
Detecting the giant catfish
A new method of eDNA sampling for detecting threatened tropical species in difficult environments shows effective results in conservation management. Water samples are collected in reservoirs and confirm is the species is present. The giant catfish is endemic to the Mekong Basin and historically represented from northern Laos to the southern coast of Vietnam. The migration patterns and spawning locations are not sufficiently certain; some nursery locations are believed to be accurate.
Fishing has been, and possibly remains a huge risk to the number of population in giant