The video shows a fish swimming in an aquarium. The fish is seen swimming around the tank, exploring its surroundings. The tank is filled with water and has rocks and plants inside, providing a natural habitat for the fish. The fish appears to be healthy and active, moving smoothly through the water. The aquarium is well-lit, allowing for clear visibility of the fish and its environment. The video captures the serene and peaceful ambiance of the aquarium, with the fish being the main focus of the footage.