Transcript Biology 029

Biology 029
Hydrothermal 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 probes
 First visited by DSV ALVIN in
1977
Black Smokers
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
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
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
Weird minerals make for weird
building blocks…
Why don’t they get cooked?
 Pompeii
worm
 Vent shrimp
Alvinella pompejana
Cary et al. 1998 Nature
Rimicaris exoculata
Dies at about 37 °C
 Uses behavioural
avoidance to hover
around the edges of
the vent environment

Rimicaris exoculata
avoids being cooked…
 http://www.divediscover.whoi.e
du/ventcd/
 http://www.whoi.edu/institutes
/doei/viewTopic.do?o=read&id=
119