The video shows a group of fish swimming in an aquarium. The fish are of different species, including clownfish and tangs. They are swimming around the tank, which is decorated with coral and rocks. The water is clear and the lighting is bright, highlighting the vibrant colors of the fish. The clownfish are orange with white stripes, while the tangs have blue and yellow stripes. The fish are moving in and out of the frame, sometimes swimming close to the camera and other times moving towards the back of the tank.