2 hours ago
No. 125 of #RealandEndangered is the Mekong giant catfish, which occur in the lower half of the Mekong River system, in Cambodia, Laos, Thailand, and Vietnam. These behemoths instantly caught my attention and here are a few reasons why: 1. They are the world’s largest scaleless freshwater fish. They can grow up to 10 feet (3 meters) long and weigh up to 650 pounds (300 kilograms). 2. Juveniles have the characteristic catfish barbels (“whiskers”), however these shrink as the fish ages. 3. They fall into the shark catfish family. 4. They are toothless herbivores (diet consists of plants and algae). 5. This species is highly migratory and require large stretches of river.
Since 2003, the International Union for the Conservation of Nature lists them as "critically endangered.” It is estimated that their population has dropped by 95% over the last century. Threats include overfishing, damming of tributaries, habitat loss and degradation (including destruction of spawning and breeding ground), and siltation. The species is listed on CITES Appendix I and it is illegal to harvest them in Thailand, Laos, and Cambodia. In Thailand, some fishers have even pledged to stop catching the catfish. They also occur in protected areas, however, as with other species, enforcing the laws continues to be an issue, especially with bycatch. There has been some success in captive breeding, resulting in the release of 10,000 individuals into the wild. In 2013 a pilot project to track their migration patterns was launched. Then in 2017, they turned to environmental DNA (eDNA) techniques to determine specific areas they fish have passed through.