Underwater fantasy illustration: a mermaid holds an antique lantern made of brass and glass, inside which glowing jellyfish float. The jellyfish are the only source of light: their bright bioluminescent glow in rich shades of blue, turquoise, and purple shines through the lantern's glass and illuminates the mermaid's face and hands, as well as the nearby sea plants. Around there is almost absolute darkness. No sunlight or moonlight, no rays from the surface, no ambient glow, or other luminous objects. A detailed fairytale-style illustration, expressive contrast of light and shadow, no text. The mermaid's tail is fully visible. A beautiful bright drawing. The jellyfish are drawn carefully.