Many Deep-Sea Animals Make Their Own Light

Green fluorescent protein, first isolated from the jellyfish Aequorea victoria, became a key tool for tracking molecules in living cells.

Single-celled dinoflagellates flash blue when disturbed, which makes breaking waves and swimmers' movements glow at night.

Deep-sea anglerfish carry a light-producing lure, and its glow comes from symbiotic bacteria living inside it.

The reaction is extremely efficient and produces almost no heat, which is why the light is often called cold light.