Bioluminescence in Land Animals

Most of the world's bioluminescence exists in the ocean, not on land. But there are bioluminescent land animals, including insects, centipedes, millipedes and worms. In contrast to the marine environment, where the predominant bioluminescence color is blue, in the terrestrial environment, green is the predominant bioluminescence color.

One of the most widely-known luminescent insects is the firefly. There are more than 2,000 species of fireflies, or lightning bugs, and they are actually winged beetles, not flies.

       

Glow worms are actually just fireflies (Lampyridae) in their larvae stage. Fireflies glow even when they are just tiny, wingless larvae. They radiate a single, unwavering green light on their foreheads which serves as a warning to predators. The larvae of the glow worm beetle, or Phengodidae beetle, are also known as glow worms. The trunks of the females and larvae of these beetles have bioluminescent organs that emit yellow or green light. In the dark, these glow worms glow in a fascinating stripped pattern.

The Diplocardia longa earthworm exudes a sticky, bioluminescent slime when it's disturbed as a way to scare off predators. This excretion contains luciferin, the same light-emitting chemical found in fireflies. The earthworms can grow to be up to 20 inches long and are found in the southern United States.

                                            

The Quantula striata (also known as Dyakia striata) is the only land snail known to produce light. Found in Singapore and Malaysia, the snail's eggs and newly hatched juveniles continuously glow in the dark. As they mature, the snails switch to only glowing in flashes when something disturbs them.

                                              

It is also interesting to note that there are no luminous flowering plants, birds, reptiles, amphibians or mammals.