In the video, a clownfish is seen swimming around a rock structure in an aquarium. The fish is bright orange with white stripes and a red nose. It moves gracefully through the water, exploring different parts of the rock structure. The aquarium is well-lit, and the water is clear, allowing for a good view of the fish and its surroundings. The rock structure has various crevices and ledges, providing the fish with plenty of places to explore. The fish seems to be healthy and active, and its movements are smooth and fluid. Overall, the video captures the beauty and grace of the clownfish in its aquatic environment.