013-Bioluminescence

DinoflagellatesTrinidad

dysphotic

100m

The Electromagnetic Radiation Spectrum

Only green and blue wavelengths pass through water a great distance.

Light Penetration

in the Ocean

Light Penetration

in the Ocean

What color/wavelength of light will animals use?

dysphotic

Types of light production: 1. incandescence – light bulb2. 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 shark2. Numerous photophores 1000’s3. Make own luminescence4. 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 (dragonfish)

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.

Duncecap or helmet jellyPeriphylla periphylla

Bamboo coral Keratoisis flexibilis

ostracod

Dinoflagellate

Ctenophore

pterapods

Firefly squid

Deep sea squid

Deep sea glass squidTeuthowenia pellucida

Deep sea gulper

Photophores on ventral surface

Deep sea viper fish & deep sea shrimp

Black Devil Angler Fish

lure

angler fish

Inquiry

1. Define bioluminescence.2. Who produces bioluminescence?3. What is the difference between

intrinsic and bacterial bioluminescence?

4. What is the blink and run method?5. What is countershading?6. What is the evolutionary

advantage of bioluminescence in bacteria?