I'm fascinated by these claims that this species of giant gourami likes high flowing rivers. I was always led to believe that all gouramis prefer still or extremely slow flowing waters, even their much smaller community tank cousins.
Their shape alone tells you they aren't suited to high flow environments. They are also labyrinth fish. Evolution has given them this ability to breathe air from the surface when the oxygen levels are low. Since when are oxygen levels low in fast flowing rivers!!!
Even my RTGG sulks in a less turbulent area of the tank when my powerhead intermittently comes on. When it goes off he comes back out.
All the clues are there in my eyes.
But I'm happy to be proven wrong, especially if the locals of these catchment areas do indeed regularly catch them in fast flowing turbulent areas.