Transcript PPT

Chemosynthetic
Environments
Katrina Pekar
What is it?
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Chemosynthesis: The synthesis of organic compounds
by energy derived from chemical changes or reactions
Autotrophic bacteria synthesize the organic compounds
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Other animals either have a symbiotic relationship with the
bacteria or prey upon other fauna
http://www.rci.rutgers.edu/~
carr/2003Lecture%2015%20
MOR.pdf
Two Major Examples
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Hydrothermal vents
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Mid-ocean ridges
Cold seeps
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Trenches, oil/natural gas rich areas of sea floor,
brine pools, areas of methane hydrate
Comparison
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Hydrothermal vents
Sulfide-rich
High temps
High pH (2.8)
Associated with black
smokers
www.mbari.org/news/news_releas
es/2002/oct17_vrijenhoek.html
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Cold seeps
Methane-rich
Very low temps
Normal ocean pH
Can be anywhere
methane seeps out
www.mbayaq.org/efc/living_species/
default.asp?inhab=199
Hydrothermal vent fauna (modern)
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Blind shrimp, giant white
crabs, bivalves, a variety
of tube worms
“Naked” snails: High pH
prevents shell formation
Specialized
characteristics
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Metal-binding proteins in
body systems
Metal expelling mucus in
tubeworms
http://www.rci.rutgers.edu/~carr/2003Lecture%201
5%20MOR.pdf
Cold Seep fauna (modern)
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Similar to vent fauna
Higher diversity
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Less harsh environment or less limited dispersal
Still have autotrophic bacteria at the base of the
food web
Ancient fauna example from Silurian
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Bacteria, again
Brachiopods and
monoplacophorans
Relatives of tube worms
Example from Yaman
Kasy mine in the Urals
of Russia: volcanogenic
massive sulfide
http://www.nhm.ac.uk/mineralogy/i
ntro/project5/
In conclusion…
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Thought to be origins of life on the Earth
Many life forms unique to environment (300+
species to date, 95% new to science)
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Some have changed little from ancient relatives
Several fossilized analogs exist and are being
studied