The video shows a large fish swimming in an aquarium. The fish is dark gray with a silver belly and white-edged fins. It has a somewhat shark-like appearance. In the center of the tank, there's a large structure made of stacked, porous rocks. The aquarium has a sandy bottom, and a few small fish are visible. In the background, reflections of people and other fish tanks can be seen. One person is holding up a phone, presumably taking a picture or video of the fish.