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Bioluminescence. Ocean Zones. Light penetration in the ocean. The Electromagnetic Radiation Spectrum. Only green and blue wavelengths pass through water a great distance. Light Penetration in the Ocean. Ocean Zones. What color/wavelength of light will animals use?. Light .
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Light penetration in the ocean The Electromagnetic Radiation Spectrum Only green and blue wavelengths pass through water a great distance.
Ocean Zones What color/wavelength of light will animals use?
Light • Types of light production: • incandescence – light bulb • 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.
Bioluminescence Chemical Reaction luciferase Luciferin + O2 oxyluciferin + light
Types of Bioluminescence • Bacterial • Intrinsic Photobacterium
Photophore (bacterial) Light emitting organ
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: • Widely distributed, ex. Cookie cutter shark • Numerous photophores 1000’s • Make own luminescence • 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
What are the advantages of using bioluminescence?
Function of Bioluminescence • 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.
Communication squids- looking for mates.
Predation Some predators can lure prey by mimicking signals of prey. Other predators dangle a lure to attract prey.
Defense mid-water squid releases a bioluminescent cloud to startle and confuse predators. Photoblepharon- blink and run method.
Other bioluminescent animals Ctenophore
Firefly squid Deep sea squid
Photophores on ventral surface Deep sea gulper