biology 029

Biology 029Hydrothermal vents:

Life in the hot, deep sea

Pre-1977 view of life

Pre-1977 view of life in the oceans

Suspicion that there were hydrothermal vents… ‘Hot’ zones from towed probesFirst visited by DSV ALVIN in

1977

Black Smokers

Characteristics of black smokers

Water leaves at 273 °CRapidly cools to ambientLeaves a zone at about 20 °C

‘Black smoke’ – plume of precipitates

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

The trophosome is packed with chemosynthetic bacteria

Tentacles harvest metal sulfides, CO2 and O2 from the water

Blood contains both hemoglobin (carries oxygen) and a molecule to carry sulfides

The bacteria provide food to the tubeworm

Weird minerals make for weird building blocks…

Why don’t they get cooked?Pompeii worm Vent shrimp

Alvinella pompejana

Cary et al. 1998 Nature

Dies at about 37 °C Uses behavioural

avoidance to hover around the edges of the vent environment

Rimicaris exoculata

Rimicaris exoculata avoids being cooked…

http://www.divediscover.whoi.edu/ventcd/

http://www.whoi.edu/institutes/doei/viewTopic.do?o=read&id=119