1, the color shades are different: the color of river eel is relatively lighter, usually light gray or light brown, while the color of river eel is relatively darker, usually dark brown or black.
2, the distribution of spots and plaques is different: river eels have more spots and plaques on the surface of the body, and the overall appearance is relatively rough, while the river eel's body surface is relatively smooth, without too many spots and plaques, and the overall appearance is relatively elongated.