and migrate upstream to spawn. They live primarily in the main channel of the river, where the water depth is over , 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, fishers 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. A 150 kg individual was found in a Kelantan river in Malaysia, it is believed to have been released illegally. Understanding of the species’ migration pattern is incomplete. The fish are thought to rear primarily in the Mekong and Cambodia's Tonle Sap lake and migrate hundreds of miles north to spawning grounds in Thailand. Spawning fish in the upper Cambodia are being over harvested. Fragmentation caused by infrastructure development of dams are becoming increasingly common posing threats to larval fish and reducing breeding abilities. Overfishing, damming, destruction of spawning, and breeding grounds and siltation have taken a toll on the species' habitat. Feeding As fry, this species feeds on zooplankton in the river and is known to be cannibalistic. After about 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. The Mekong giant catfish are toothless herbivores that live off of the plants and algae in the river. One scientific study found zooplankton and phytoplankton in their stomach contents. In captivity Mekong giant catfish are now successfully bred in Thailand, they are often hybridised with the iridescent shark to make the Mekong iridescent shark. They also have a short body form like the paroon shark and iridescent shark. They are also bred for the aquarium trade. Ownership and importation of the fish has been restricted in various states of Australia due to fears it could become an invasive species. As a sport fish Mekong giant catfish along with the giant barb, giant pangasius, redtail catfish and alligator gar are a common sport fish in exotic fishing ponds in Thailand, Malaysia, and Vietnam. This is because of their giant size and because they often put up a strong fight after getting hooked. Conservation Endemic to the lower half of the Mekong River, this catfish