The video shows a seahorse swimming in the water. The seahorse is a small fish with a curled tail and a head shaped like a horse's head. It is swimming near a green plant in the water. The seahorse is moving slowly and gracefully, and its body is covered in small scales. The water is clear, and the seahorse's movements are smooth and effortless. The green plant provides a nice contrast to the seahorse's body, making it stand out in the video.