The video shows a group of small fish swimming in an aquarium. The fish are silver in color and have a sleek, streamlined body shape. They are swimming around a rocky structure that is part of the aquarium decor. The rocks are dark gray and appear to be made of a stone-like material. The fish are moving in different directions, some swimming close to the rocks while others are near the surface of the water. The aquarium seems to be well-lit, and the water is clear, allowing for a good view of the fish and their surroundings.