How do jellyfish use bioluminescence to discourage predators?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

time-lapse photo of fireflies — Bioluminescence Time-lapse image of fireflies in the Catskill Mountains, New York. Firefly light is a cold light, with approximately 100 percent of the energy given off as light and only a minute amount as heat. Only light in the visible spectrum is emitted.

Jellyfish utilize bioluminescence primarily as a deterrent to discourage predators. More than half of all jellyfish species possess this ability, often using the light to confuse potential threats. Some species further enhance this defense by secreting a glowing, or lambent, mucus to distract or disorient predators.1

This light production is a chemical reaction involving the oxidation of a molecule called luciferin, a process catalyzed by the enzyme luciferase. In specific cases, such as the jellyfish Aequorea victoria, the organism produces a green glow around the rim of its bell by passing blue light through a compound known as green fluorescent protein (GFP).21