Summary
Light produced by luciferin and luciferase reactions in deep-sea fish, fireflies and jellyfish.
In depth
Luciferin is oxidised by luciferase, giving cold light. It is used for predator evasion (counter-illumination, decoys), attraction of prey (anglerfish lure) and mating signals (fireflies). It evolved independently dozens of times; about 75 percent of deep-sea animals produce light.
Bioluminescence needs oxygen. Colours are mostly blue-green in the sea. Symbiotic bacteria supply light in some animals.
Example: flashlight fish use bacteria in their cheeks.
Light production is found in about 76 percent of deep-sea animals and evolved independently more than 40 times. Mechanisms involve luciferin plus luciferase and oxygen (and ATP in fireflies), or photoproteins (aequorin from jellyfish, which led to the discovery of green fluorescent protein, GFP, a tool of cell biology; Nobel Prize 2008). Some species host luminous bacteria: the Hawaiian bobtail squid uses Vibrio fischeri light to disguise its shadow (counter-illumination).
Functions include luring prey (anglerfish lure), startling predators, communication and mate attraction (firefly flash patterns, with predatory Photuris females mimicking others' signals), and decoys (squid releasing luminous ink). Dinoflagellates cause glowing seas when disturbed. Luciferase is used as a reporter gene in research.
Frequently asked questions
What is Bioluminescence?
Light produced by luciferin and luciferase reactions in deep-sea fish, fireflies and jellyfish.
Which area of biology covers Bioluminescence, and how advanced is it?
Bioluminescence is one of the 53 topics in Zoology & Animal Diversity. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Animal Camouflage and Mimicry, Venom Evolution, Parasitism in Animals.
Why does Bioluminescence matter?
Bioluminescence gave biologists tools to see inside living cells.
Can you give an example of Bioluminescence?
GFP from jellyfish became a research tool.
What should I learn before Bioluminescence?
Work through the Beginner topics in Zoology & Animal Diversity first, such as Animal Kingdom, Vertebrates and Invertebrates, Sponges, then return to Bioluminescence. Advanced topics assume the Intermediate vocabulary.
What topics are related to Bioluminescence?
The closest topics to Bioluminescence are Animal Camouflage and Mimicry, Venom Evolution, Parasitism in Animals, Insects. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Bioluminescence?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Bioluminescence. To practise the whole of Zoology & Animal Diversity, use the Zoology & Animal Diversity quiz.
How is Bioluminescence different from Animal Camouflage and Mimicry?
Bioluminescence: Light produced by luciferin and luciferase reactions in deep-sea fish, fireflies and jellyfish. Animal Camouflage and Mimicry: Colour and form evolve to hide or imitate other species, as in Batesian and Mullerian mimicry. Read both side by side and note what each one explains.
How should I study Bioluminescence step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Animal Camouflage and Mimicry and explain the difference aloud. Finally, take the Zoology & Animal Diversity quiz and come back to this page for any question you miss.