A dreamlike underwater environment, with crystal-clear waters and soft natural light filtering from the ocean surface, colorful fish swimming in the background, coral reefs, smooth rocks, and gently swaying seaweed. At the center, a regular-sized, fully transparent fish swimming freely in its natural habitat. Its body, shimmering like oceanic crystal, reveals a miniature self-contained ecosystem entirely enclosed within, with no elements protruding or breaking through its external structure. Inside the fish, a waterfall cascades from a mossy hill, flowing over smooth stones into a glowing pond, surrounded by tiny trees, exotic plants, bioluminescent mushrooms, and soft internal lights. The entire ecosystem remains strictly inside the fish’s body, creating a magical contrast between the calm simplicity of the marine surroundings and the vibrant complexity of the inner world. Captured in a hyper-realistic photographic style with cinematic underwater lighting, soft depth of field, and exquisite detail.