Here is a detailed description of the video: The video shows a black and red Betta fish swimming in an aquarium. The fish is the main subject of the video. The tank is filled with green plants, giving it a lush and vibrant appearance. There is a small Buddha figurine placed at the bottom of the tank. The aquarium's glass is visible at the top of the frame. The lighting suggests a source above the tank, casting a slight glare and illuminating the scene.