The video shows a black catfish swimming in a tank filled with gravel. The catfish is seen swimming around the tank, moving its fins and tail. The tank appears to be well-maintained, with clear water and no visible debris. The catfish is the only fish in the tank, and it moves freely without any obstacles. The gravel on the bottom of the tank is multicolored, and there are some plants and rocks in the background. The catfish has a sleek body and a long tail, and it moves smoothly through the water.