Transcript Bioluminescence

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
Annelid (segmented worm).
Lives 3000 m below surface.
Ctenophore Deiopea
Comb Jelly
Dinoflagellates
Small Squid
Enlargement of Photophores
(light emitting organs)
Vampire Squid
(Vampyroteuthis infernalis)
Anglerfish
Dragonfish
Hatchetfish
So….why do they do it?
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.
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.
• 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.
• http://www.youtube.com/watch?v=9frgs8lU
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Copy these questions down,
and answer in your notes
Bioluminescence Questions
1. How is bioluminescence produced?
2. List six creatures that emit bioluminescence
3. Describe the three reasons why creatures in
the ocean use bioluminescence.
4. What colour is most bioluminescence and what
is an exception?
5. Why might creatures emit a bioluminescence
liquid?