IR Home
AME
Home
Editors
Forthcoming
Information
Subscribe
Journals
Home
MEPS
AME
CR
DAO
ESEP
Search
Subscribe
Book Series
EE Books
Top Books
Order
Discussion Forums
Home
Research
Endangered Species Programs
Institutions
International Ecology Institute
Eco-Ethics International Union
Foundation
Otto Kinne Foundation
| |
AME 27:195-202 (2002)
|
Abstract
|
![](../../../../images/hline.gif)
Food concentration-dependent regulation of food selectivity of interception-feeding bacterivorous nanoflagellates
Jens Boenigk1,*, Carsten Matz2, Klaus Jürgens2, Hartmut Arndt3
1Austrian Academy of Sciences, Institute for Limnology, Mondseestr. 9, 5310 Mondsee, Austria
2Max Planck Institute for Limnology, Department of Physiological Ecology, 24306 Plön, Germany
3Department of General Ecology and Limnology, Zoological Institute, University of Cologne, 50923 Cologne, Germany
*E-mail: jens.boenigk@oeaw.ac.at
![](../../../../images/hline.gif)
ABSTRACT: The significance of food concentration for selectivity was analyzed by video microscopy for 3 species of interception-feeding bacterivorous nanoflagellates of the genera Spumella, Ochromonas and Cafeteria. Inert beads and
live bacteria were offered simultaneously at 5 different concentrations. The fate of individual prey particles was recorded during the stages of the particle-flagellate interaction: capture, ingestion, digestion and egestion. The experiments revealed
passive and active selection mechanisms that were regulated separately. Selective food uptake depended strongly on food concentration, whereas differential digestion was independent of the food concentration and independent of the number of previously
ingested food particles. In addition to active selection of food items, passive selection occurred due to the different contact probabilities of prey. In contrast to the chrysomonads Spumella sp. and Ochromonas sp., the bicosoecid
Cafeteria sp. showed no significant active selection, neither during food uptake nor during digestion. The results imply that it is more efficient for some interception-feeding flagellates to feed unselectively all particles that can be
morphologically ingested and then to attempt to digest these particles. Active selection in advance may only be efficient when the particle concentration is sufficiently high such that vacuole formation becomes time limiting.
KEY WORDS: Ecology · Feeding process · Grazing · Microbial food web · Optimal foraging · Prey handling · Protists
Full text in pdf format
![](../../../../images/hline.gif)
Published in AME Vol.
27, No. 2
(2002) on March 15
Print ISSN: 0948-3055; Online ISSN: 1616-1564.
Copyright © Inter-Research, Oldendorf/Luhe, 2002
|