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Growth rates of common pelagic ciliates in a highly eutrophic lake measured with a modified dilution method Cover

Growth rates of common pelagic ciliates in a highly eutrophic lake measured with a modified dilution method

Oceanological and Hydrobiological Studies
Volume 45 (2016): Issue 2 (June 2016)
By: Krzysztof Rychert  
Open Access
|Jun 2016

Figures & Tables

Figure 1

Growth responses of ciliates to gradual dilution observed during approx. 4 hours of incubation performed around noon and midnight on three occasions in Lake Gardno. Through dilution, grazing pressure decreased toward zero and the apparent growth rate approximates the specific growth rate (y-intercept). The date of the experiments and statistical significances are depicted on the graphs. The dashed line represents the 95% confidence interval. In the experiment with Cyclidium sp. performed around noon in June 2012 (E), the grazing pressure was relaxed only in more diluted treatments, thus the additional grazing curve was plotted for 20–60% dilutions (dotted line) that demonstrated higher statistical significance.
Growth responses of ciliates to gradual dilution observed during approx. 4 hours of incubation performed around noon and midnight on three occasions in Lake Gardno. Through dilution, grazing pressure decreased toward zero and the apparent growth rate approximates the specific growth rate (y-intercept). The date of the experiments and statistical significances are depicted on the graphs. The dashed line represents the 95% confidence interval. In the experiment with Cyclidium sp. performed around noon in June 2012 (E), the grazing pressure was relaxed only in more diluted treatments, thus the additional grazing curve was plotted for 20–60% dilutions (dotted line) that demonstrated higher statistical significance.

Figure 2

Mean diel growth rates versus growth rates estimated with the allometric equation according to Müller & Geller (1993): (1) Tintinnidium sp., (2) Rimostrombidium sp., (3) Cyclidium sp. in June 2013, (4) Cyclidium sp. in June 2012 (noon only, range of growth rates estimated with two methods of analysis (Fig. 1E). The dashed diagonal represents a 1:1 relationship.
Mean diel growth rates versus growth rates estimated with the allometric equation according to Müller & Geller (1993): (1) Tintinnidium sp., (2) Rimostrombidium sp., (3) Cyclidium sp. in June 2013, (4) Cyclidium sp. in June 2012 (noon only, range of growth rates estimated with two methods of analysis (Fig. 1E). The dashed diagonal represents a 1:1 relationship.

Environmental conditions and food resources during experiments carried out in highly eutrophic Lake Gardno_ Mean values for the incubation of whole water and 20% dilution were calculated for bacterial and flagellate abundances (see Materials and Methods)_ In the case of chlorophyll a concentration, values for whole water and 10-μm filtrates are provided, because only such small algae (up to 10 μm) represented the available food resource for the ciliates studied_

ExperimentTemp.(°C)Salinity(PSU)Ciliates(cells ml1)Chlorophyll a (μg l-1)Bacteria (106 cells ml1)Nanoflagellates (103 cells ml1)
whole water10-μm filtratewhole water20% dilutionwhole water20% dilution
21–22/09/2011midnight15.60.5967.360.97.037.045.2218.711.2
22/09/2011noon15.40.6742.261.96.285.893.2619.316.9
13/06/2012noon20.00.9211850.39.178.767.8720.314.6
13–14/06/2012midnight21.10.8411933.86.899.769.1416.012.8
28–29/06/2013midnight18.40.1730745.37.5816.414.918.115.5
29/06/2013noon18.20.1842346.88.6912.710.716.615.4
DOI: https://doi.org/10.1515/ohs-2016-0020 | Journal eISSN: 1897-3191 | Journal ISSN: 1730-413X
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Language: English
Page range: 216 - 229
Submitted on: Jul 4, 2015
Accepted on: Oct 9, 2015
Published on: Jun 22, 2016
Published by: University of Gdańsk
In partnership with: Paradigm Publishing Services
Publication frequency: 4 issues per year
Keywords:
growth,
ciliate,
dilution technique,
allometric equation,
food limitation,
diel rhythm,
Lake Gardno,
eutrophic
Related subjects:
Chemistry,
Chemistry, other,
Geosciences,
Geosciences, other,
Life sciences,
Life sciences, other

© 2016 Krzysztof Rychert, published by University of Gdańsk
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

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