The video shows a group of fish swimming around in an aquarium. The fish are of different sizes and colors, with some being larger and having more vibrant colors, while others are smaller and have more subdued colors. The fish are swimming around in different directions, some are swimming near the bottom of the tank while others are swimming near the top. The aquarium appears to be well-maintained, with clear water and no visible debris. The fish seem to be healthy and active, moving around freely and interacting with each other.