Every part of this fish is covered with snake-like armor. It's gotten to the point where you don't even know if it's right to categorize it as a fish. From the aspect of its unique evolution, it's not even inferior to Skullcanth.
It almost looks like a dragon. Who knows how to catch it? I heard the fish that live in the cave are sensitive to sounds and smells though.
In the meantime, you could try a fire lure which makes noisy sounds. The smell of charcoal from its body might also be effective.