BIOLUMINESCENCE

What is Bioluminescence?

• The production of light by living organisms as a result of a chemical reaction either within certain cells or organs OR outside the cells in some form of excretion.

• Produced by the compound luciferin and the enzyme luciferase.

Who is lighting up in the ocean? Bacteria

Dinoflagellates

Jellyfish

Squid & Octopus

Annelids (worms)

Krill & Shrimp

Seastars, Brittlestars, Sea Cucumber

In the deep ocean, where sunlight is absent, more than 90% of the animals are

luminescent !!!

Krill

Ctenophore DeiopeaComb Jelly

Annelid (segmented worm). Lives 3000 m below surface.

Dinoflagellates

Small Squid

Enlargement of Photophores (light emitting organs)

Vampire Squid (Vampyroteuthis infernalis)

Dragonfish

Anglerfish

Hatchetfish

So….why do they do it?1. Finding or Attracting Prey

• Fish such as the anglerfish use a light organ filled with bacteria that dangles from their forehead.

• Prey are attracted to the light in the same way that a fisherman might use a glowing lure for night fishing.

• Some fish use bioluminescence as a flashlight. They use light, produced by symbiotic bacteria living in an organ below their eyes, to light up potential prey.

2. Defence Against Predators• Can serve as a decoy. Some squid and shrimp produce

a luminescent glowing cloud.• When attacked by a predator, brittlestars sacrifice a part

of the body that continues to flash as the animal makes its escape.

• Where the sunlight is dim, it can be used as camouflage. • Many small plankton use flashes of light to startle their

predators in an attempt to interrupt their feeding.

3. Communication / Mating• Attract opposite sex.

• Bristle worms use bioluminescence during mating swarms, where the males will attract females to them.

• Crustaceans send out coded messages when it is time to mate.

This octopod uses its bioluminescence as a private signal for mating. Light is produced only at certain times, by a ring around the mouth of females.

Are bioluminescent animals found only in the ocean?

• There are a few species on land.

– Fireflies during the summer in North America.

– Glow worms (actually fly larvae) in New Zealand.

– Railroad worms (actually beetle larvae) in South and Central America.

• But, bioluminescence is not found in freshwater lakes or rivers.

Bioluminescence Video Clip

http://www.ted.com/talks/edith_widder_the_weird_and_wonderful_world_of_bioluminescence.html#