Transcript Bioluminescence

The Electromagnetic Radiation Spectrum
Only green and blue wavelengths pass through water a great
distance.
Light
Penetration
in the
Ocean
What color/wavelength of light will animals use?
Types of light production:
1. incandescence – light bulb
2. luminescence- fluorescence bulb
What is the difference between these types of
light?
Bioluminescence: a chemical reaction
What organisms that you know of have
bioluminescence?
Bioluminescence evolved in several kingdoms.
Evolution:
In early evolution, O2 was toxic. Some
organisms were able to convert it to a nontoxic
substance, which had the tendency to produce
photons of light. This may have had a selective
advantage to some organisms.
Not found in freshwater organisms.
luciferase
Luciferin + O2
oxyluciferin + light
• Bacterial
• Intrinsic
Photobacterium
(bacterial)
Light emitting organ
Cephalopod Photophore
Examples of Bacterial Photophores:
• fish, few squid, Pyrosoma (tunicate)
How do they get bacteria?
• organ open to exterior (provide entrance for bacteria to
enter)
• potentially continuous luminescence
Pyrosoma
Bacterial photophores- 3 genera
•
•
•
Photobacterium (symbiotic relationship)
Achromabacteria (2 types of squid use bacteria, the
rest (17) have make their own luminescence)
Beneckea (not associated with symbiotic relationship)
Squid Euprymna- squid hatches w/out bacteria; w/in hours it
is infected w/natural populations of bacteria
Tunicate- Pyrosoma- bacterial symbiont (intracellular)
Examples of fish that have bacterial photophores:
• Anglerfish (ceratioids)
• Pinecone fish (Monocentrids)
• Lantern eyes/flashlightfish (Anomalopids)
• Ponyfishes/slipmouths (Leiognathids)
• Ichthyococcus
Intrinsic photophores:
1. Widely distributed, ex. Cookie cutter shark
2. Numerous photophores 1000’s
3. Make own luminescence
4. Control output of light (on and off)
Control of Bioluminescence:
They can control biolum intensity by controlling
blood supply to light organ (i.e., control the amt of
O2 -- O2 decreases light intensity decreases)
Light control using a shield
• Lid
• Vascular control
• Rotation of organ
• Reproductive advantage
• Countershading
• Escape and avoid predation
• Species recognition
• Feeding
• In evolution
Some mesopelagic
copepod species are
red/black in color. Why?
Malacosteus, possess a cheek
photophore that emits a red light, which
allows it to detect red animals.
squids- looking for mates.
Some predators can lure prey by mimicking
signals of prey. Other predators dangle a
lure to attract prey.
mid-water squid releases a bioluminescent
cloud to startle and confuse predators.
Photoblepharon- blink and run method.
Ctenophore
pterapods
Firefly squid
Deep sea squid
Photophores on
ventral surface
Deep sea gulper
Deep sea viper fish
angler fish