Animal Diversity lecture 15 - deep sea vents

Question 1

Where do deep sea vents form

Answer 1

• Form along mid-ocean ridges (1500-4000m)

- Ridges at boundaryies of tectonic plates (>75k km)

Question 2

How do deep sea vents form

Answer 2

• sea floor spreads + cracks appear in some areas
• water flows into cracks and gets super heated
• Comes out in plumes full of nutrients , full of chemicals, rich in sulphides

Question 3

How do deep sea vents support the ecosystems that form around them

Answer 3

Vent fluid rich in minerals supports the ecosystem

• chemicals are basis of food chain
• high energy system at high temperatures

Question 4

What are the primary producers in DSVs

Answer 4

• Primary producer = chemoautotrophic micro-organisms
• oxide sulphides are used to create carbon compounds
• microorganisms are consumed directly or form symbiotic relationships

Question 5

How does biodiveristy differ between the deep sea environment and deep sea vents.

Answer 5

Deep sea -> high animal diversity but low individual number

Vents -> low number of species but high densities, typical of productive environments (salt marshes, estuaries etc.)

Question 6

Conditions of deep sea vent systems

Answer 6

extreme temperatures and pressures, toxic minerals, and lack of sunlight

Question 7

Examples of adaptations to cope with harsh conditions

Answer 7

E.g. yeti crab
- hair is actually filamentous bacteria to protect from high temperatures, also seen on other animals that live by vents.

Question 8

Giant tube worm (polychaete) features - example of deep sea vent living

Answer 8

- 3m long , rapid growth rate 
 (80cm a year) 
- No gut 
- Tissues are stuffed full of 
  symbiotic bacteria which 
  oxidise the sulphides
- Plumes used to collect 
  H2S and 02 which is then 
  transported to the bacteria. 
- carbon compounds 
  produced and used by the 
  worm

Question 9

another example of deep sea vent life

Answer 9

Pompeii Worm (Alvinella pompeyana)

• Gallery dweller
• Tolerates extremely high temp (80oC)
• Deposit feeder
• Dorsal surface is colonised by bacteria (filamentous hair)
• V hard to study because they live in such high pressure, die when brough to surface

Question 10

How many species of vent fauna are there

Answer 10

• over 500 new species
• More than 90% from vent communities only
• Others from deep sea, chemosynthetic ecosystems

Question 11

chemosynthetic ecosystem

Answer 11

An ecosystem that relies on Chemosynthesis

• the conversion of carbon (usually carbon dioxide or methane) into organic matter using inorganic molecules (hydrogen or hydrogen sulfide) or methane as an energy source.
  e. g. cold seeps and deep sea vents