The line-feathered electric eel, also known as black devil fish, is called Black Ghost Fish in English, and its more popular name in China is "magic knife" or "Kuroha". Aggressive, like to walk at night, the whole body is as dark as ink, the swimming posture is clever and wonderful, and the hunting speed is extremely fast. The whole body is dark, the head is pointed, the caudal fin is slender as a rod, and the caudal fin has two white circles. Feel the water flow, obstacles and food by the weak current in the body, which has a strange shape. The figure is relatively flat, the back is smooth and curved, and the ventral fin is connected with the gluteal fin, which is wavy until the tail, like a black lace to outline the curve of the fish.