The video shows a seahorse swimming in a tank. The seahorse is a small, fish-like creature with a curled tail and a long snout. It is swimming near a rock formation in the tank, which is covered in algae and other marine life. The water in the tank is clear, and there are bubbles visible in the background, indicating that the tank is well-aerated. The seahorse moves slowly and gracefully, using its tail to hold onto the rocks. The lighting in the tank highlights the seahorse's unique features, making it easy to see its movements and the details of its body.