How do jellyfish react to the dark?

Bioluminescence is the production and emission of light by a living organism. It is a common phenomenon in the ocean, where it is estimated that over 90% of all animals produce light. Jellyfish are one of the most well-known bioluminescent animals.

There are many different ways that jellyfish produce light. Some jellyfish have special cells called photocytes that contain a protein called luciferin. When luciferin is exposed to oxygen, it reacts to produce light. Other jellyfish produce light by using a chemical called aequorin. Aequorin is a protein that binds to calcium ions. When calcium ions are present, aequorin releases light.

Jellyfish use bioluminescence for a variety of purposes. Some jellyfish use it to attract prey. Others use it to deter predators. Still others use it to communicate with each other.

In the dark, jellyfish can produce a dazzling display of light. This light can be seen from the surface of the water, and it can even be seen from space. Bioluminescence is a truly amazing phenomenon that is one of the wonders of the natural world.