Chemosynthetic Environments Katrina Pekar

What is it? Chemosynthesis: The synthesis of organic compounds by energy derived from chemical changes or reactions Chemosynthesis: The synthesis of organic compounds by energy derived from chemical changes or reactions Autotrophic bacteria synthesize the organic compounds Autotrophic bacteria synthesize the organic compounds Other animals either have a symbiotic relationship with the bacteria or prey upon other fauna Other animals either have a symbiotic relationship with the bacteria or prey upon other fauna carr/2003Lecture%2015%20 MOR.pdf

Two Major Examples Hydrothermal vents Hydrothermal vents Mid-ocean ridges Mid-ocean ridges Cold seeps Cold seeps Trenches, oil/natural gas rich areas of sea floor, brine pools, areas of methane hydrate Trenches, oil/natural gas rich areas of sea floor, brine pools, areas of methane hydrate

Comparison Hydrothermal vents Sulfide-rich Sulfide-rich High temps High temps High pH (2.8) High pH (2.8) Associated with black smokers Associated with black smokers Cold seeps Methane-rich Very low temps Normal ocean pH Can be anywhere methane seeps out default.asp?inhab=199 es/2002/oct17_vrijenhoek.html

Hydrothermal vent fauna (modern) Blind shrimp, giant white crabs, bivalves, a variety of tube worms Blind shrimp, giant white crabs, bivalves, a variety of tube worms “Naked” snails: High pH prevents shell formation “Naked” snails: High pH prevents shell formation Specialized characteristics Specialized characteristics Metal-binding proteins in body systems Metal-binding proteins in body systems Metal expelling mucus in tubeworms Metal expelling mucus in tubeworms 5%20MOR.pdf

Cold Seep fauna (modern) Similar to vent fauna Similar to vent fauna Higher diversity Higher diversity Less harsh environment or less limited dispersal Less harsh environment or less limited dispersal Still have autotrophic bacteria at the base of the food web Still have autotrophic bacteria at the base of the food web

Ancient fauna example from Silurian Bacteria, again Bacteria, again Brachiopods and monoplacophorans Brachiopods and monoplacophorans Relatives of tube worms Relatives of tube worms Example from Yaman Kasy mine in the Urals of Russia: volcanogenic massive sulfide Example from Yaman Kasy mine in the Urals of Russia: volcanogenic massive sulfide ntro/project5/

In conclusion… Thought to be origins of life on the Earth Thought to be origins of life on the Earth Many life forms unique to environment (300+ species to date, 95% new to science) Many life forms unique to environment (300+ species to date, 95% new to science) Some have changed little from ancient relatives Some have changed little from ancient relatives Several fossilized analogs exist and are being studied Several fossilized analogs exist and are being studied