In the video, there is a fish swimming in a tank. The fish is grey and has a red head. It is swimming around the tank, which is filled with water and has a gravel bottom. The fish appears to be healthy and is moving around the tank freely. The tank is well-lit, and the water is clear, allowing for a good view of the fish and its surroundings. There are no other fish or objects in the tank, and the fish seems to be the only living creature in the tank. The fish is swimming near the surface of the water, occasionally coming close to the glass of the tank. The fish's movements are smooth and graceful, and it appears to be enjoying its time in the tank. Overall, the video provides a peaceful and calming view of a fish swimming in a tank.