Acceso abierto

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

Krzysztof Rychert
Krzysztof Rychert
   | 22 jun 2016
Oceanological and Hydrobiological Studies's Cover Image
Acerca de este artículo
Artículo anterior
Artículo siguiente
Cite
Article Category: Original research paper
Publicado en línea: 22 jun 2016
Páginas: 216 - 229
Recibido: 04 jul 2015
Aceptado: 09 oct 2015
DOI: https://doi.org/10.1515/ohs-2016-0020
© Faculty of Oceanography and Geography, University of Gdañsk, Poland. All rights reserved.
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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.

Experiment Temp.(°C) Salinity(PSU) Ciliates(cells ml1) Chlorophyll a (μg l-1) Bacteria (106 cells ml1) Nanoflagellates (103 cells ml1)
whole water 10-μm filtrate whole water 20% dilution whole water 20% dilution
21–22/09/2011 midnight 15.6 0.59 67.3 60.9 7.03 7.04 5.22 18.7 11.2
22/09/2011 noon 15.4 0.67 42.2 61.9 6.28 5.89 3.26 19.3 16.9
13/06/2012 noon 20.0 0.92 118 50.3 9.17 8.76 7.87 20.3 14.6
13–14/06/2012 midnight 21.1 0.84 119 33.8 6.89 9.76 9.14 16.0 12.8
28–29/06/2013 midnight 18.4 0.17 307 45.3 7.58 16.4 14.9 18.1 15.5
29/06/2013 noon 18.2 0.18 423 46.8 8.69 12.7 10.7 16.6 15.4
eISSN:
1897-3191
Idioma:
Inglés
Calendario de la edición:
4 veces al año
Temas de la revista:
Chemistry, other, Geosciences, Life Sciences
RSS Feed de revista