The video shows a large fish swimming in a tank. The fish has a long body and is mostly dark in color. It is swimming around the tank, which has a gravel bottom. The tank appears to be well-lit, and the fish is the only visible creature in the tank. The fish moves smoothly through the water, occasionally turning its body or fins. The tank seems to be a home aquarium, and there are no other objects or decorations visible in the video.