LECTURE 25 OUTLINE (Deep Sea & Hydrothermal Vent Communities – Nov. 21, 2006)

Life Zones (profile view)

Open-ocean (The Deep) Twilight zone (54:03- 1:00:50): • Sperm whale -- depth of squid? • Changes with depth? • Main strategy of most animals at depth: • Huge eyes – why needed? • Why no hard body parts needed at depth? • Use of stinging cells • Use of bioluminescence to avoid predation from below

Dark zone (1:00:50-1:16:10) • Why large eyes not needed at depth? • Predation strategy of Fangtooth • Why is red color an advantage? • Another method of detecting prey • Predation strategy of Gulper Eel? • How is bioluminescence produced? • #1 reason for bioluminescence • #2 reason for bioluminescence • Unusual mating strategy of male Angler Fish • Blue headlights • Advantage of red headlights • #3 reason for bioluminescence • depth charges! • What is the largest migration on planet, and why does it occur? • Photic zone description • Food source of most organisms that live below 150 meters

Mid-ocean ridge (1:31:15-1:36:43) • Dimensions of MOR • When explored for first time? • Temperature of water? • List of organisms seen at vents: • How is energy acquired? • Why is mobility required? • Potential origin of life on earth?

CHEMOSYNTHESIS: H2O + CO2 + H2S  Organic Matter + O2

Hydrothermal vents are one of the most spectacular features on the seafloor. They form in places where there is volcanic activity, such as along the Mid-Ocean Ridge. Water seeps through cracks in the seafloor and is heated by molten rock deep below the ocean crust to as high as 400°C. The hot fluid rises to the surface and gushes out of the vent openings. This hydrothermal fluid carries with it dissolved metals and other chemicals from deep beneath the ocean floor.