Biology 029

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Biology 029

• Hydrothermal vents
• Life in the hot, deep sea

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Pre-1977 view of life
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Pre-1977 view of life in the oceans
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Suspicion that there were hydrothermal vents

• Hot zones from towed probes
• First visited by DSV ALVIN in 1977

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Black Smokers
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Characteristics of black smokers
Black smoke plume of precipitates
Water leaves at 273 C Rapidly cools to
ambient Leaves a zone at about 20 C
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Where does the energy come from?

• Chemosynthesis (Chemoautotrophy)
• Bacteria utilise the chemical energy in the metal
  sulfides to reduce carbon into forms useable to
  organisms

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Tentacles harvest metal sulfides, CO2 and O2 from
the water
Blood contains both hemoglobin (carries oxygen)
and a molecule to carry sulfides
The trophosome is packed with chemosynthetic
bacteria
The bacteria provide food to the tubeworm
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Weird minerals make for weird building blocks
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Why dont they get cooked?

• Pompeii worm
• Vent shrimp

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Alvinella pompejana
Cary et al. 1998 Nature
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Rimicaris exoculata

• Dies at about 37 C
• Uses behavioural avoidance to hover around the
  edges of the vent environment

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Rimicaris exoculata avoids being cooked
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• http//www.divediscover.whoi.edu/ventcd/
• http//www.whoi.edu/institutes/doei/viewTopic.do?o
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