The
protista feed on the bacteria in the water column
The
predation rates were assessed by measuring the numbers of bacteria
and cyanobacteria marked with fluorescent dye (and killed by the heat)
in the digestive vacuolae of protists, their natural predators.
The
results showed that on the average, flagellates ingest 27%
of the total bacterial production and that ciliates play a
much smaller role, since they ingest only 0.4% of the total
bacterial ingestion by protists.
|
Protists
ingest on the average 3,2 times more cyanobacteria than bacteria, which is in good agreement with the ratio
between the squares of the respective apparent diameters (Fenchel
1982).
|
|
|
Quantity
ingested by protists
|
Apparent
diameter
|
|
Bacteria
|
1.74±0.15 nl
flagellate-1h-1
|
0.47
µm
|
|
Cyanobacteria
|
5.53±0.66
nl flagellate-1h-1
|
0.87
µm
|
|
|
Legend:
a mixotrophic ciliate
(i.e., one capable of absorbing organisms and of
effecting photosynthesis). Note the chloroplasts of
ciliated species (coloured orange), and the
recently ingested bacteria (coloured green). |
This
page was
based on
:
González JM, Torréton J-P, Dufour P, Charpy L. (1998) Temporal and
spatial dynamics of the pelagic microbial foodweb in an atoll
lagoon. Aquatic Microbial
Ecology 16:53-64
Références
citées:
Fenchel T (1982) The
bioenergetics of a heterotrophic microflagellate. Ann. Inst. Oceanogr. 58:55-60
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Atoll_site_