TY - JOUR A1 - Weisse, Thomas A1 - Berendonk, Thomas U. A1 - Kamjunke, Norbert A1 - Moser, Michael A1 - Scheffel, U. A1 - Stadler, P. A1 - Weithoff, Guntram T1 - Significant habitat effects influence protist fitness evidence for local adaptation from acidic mining lakes JF - Ecosphere : the magazine of the International Ecology University N2 - It is currently controversially discussed if the same freshwater microorganisms occur worldwide wherever their required habitats are realized, i.e., without any adaptation to local conditions below the species level. We performed laboratory experiments with flagellates and ciliates from three acidic mining lakes (AML, pH similar to 2.7) to investigate if similar habitats may affect similar organisms differently. Such man-made lakes provide suitable ecosystem models to test for the significance of strong habitat selection. To this end, we analyzed the growth response of three protist taxa (three strains of the phytoflagellate Chlamydomonas acidophila, two isolates of the phytoflagellate Ochromonas and two species of the ciliate genus Oxytricha) by exposing them to lake water of their origin and from the two other AML in a cross-factorial design. Population growth rates were measured as a proxy for their fitness. Results revealed significant effects of strain, lake (= habitat), and strain X habitat interaction. In the environmentally most adverse AML, all three protist taxa were locally adapted. In conclusion, our study demonstrates that (1) the same habitat may affect strains of the same species differently and that (2) similar habitats may harbor ecophysiologically different strains or species. These results contradict the 'everything is everywhere' paradigm. KW - allopatric speciation KW - Chlamydomonas acidophila KW - ciliates KW - everything is everywhere KW - flagellates KW - freshwater microbes KW - habitat-species interaction KW - local adaptation KW - Ochromonas spp. KW - Oxytricha spp. Y1 - 2011 U6 - https://doi.org/10.1890/ES11-00157.1 SN - 2150-8925 VL - 2 IS - 12 PB - Wiley CY - Washington ER - TY - JOUR A1 - Weisse, Thomas A1 - Moser, Michael A1 - Scheffel, Ulrike A1 - Stadler, Peter A1 - Berendonk, Thomas U. A1 - Weithoff, Guntram A1 - Berger, Helmut T1 - Systematics and species-specific response to pH of Oxytricha acidotolerans sp nov and Urosomoida sp (Ciliophora, Hypotricha) from acid mining lakes JF - European journal of protistology N2 - We investigated the morphology, phylogeny of the 18S rDNA, and pH response of Oxytricha acidotolerans sp. nov. and Urosomoida sp. (Ciliophora, Hypotricha) isolated from two chemically similar acid mining lakes (pH similar to 2.6) located at Langau, Austria, and in Lusatia, Germany. Oxytricha acidotolerans sp. nov. from Langau has 18 frontal-ventral-transverse cirri but a very indistinct kinety 3 fragmentation so that the assignment to Oxytricha is uncertain. The somewhat smaller species from Lusatia has a highly variable cirral pattern and the dorsal kineties arranged in the Urosomoida pattern and is, therefore, preliminary designated as Urosomoida sp. The pH response was measured as ciliate growth rates in laboratory experiments at pH ranging from 2.5 to 7.0. Our hypothesis was that the shape of the pH reaction norm would not differ between these closely related (3% difference in their SSU rDNA) species. Results revealed a broad pH niche for O. acidotolerans, with growth rates peaking at moderately acidic conditions (pH 5.2). Cyst formation was positively and linearly related to pH. Urosomoida sp. was more sensitive to pH and did not survive at circumneutral pH. Accordingly, we reject our hypothesis that similar habitats would harbour ciliate species with virtually identical pH reaction norm. KW - Acid mining lakes KW - Growth rates KW - pH response KW - Oxytricha KW - SSU rDNA KW - Urosomoida Y1 - 2013 U6 - https://doi.org/10.1016/j.ejop.2012.08.001 SN - 0932-4739 VL - 49 IS - 2 SP - 255 EP - 271 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Weithoff, Guntram A1 - Moser, Michael A1 - Kamjunke, Norbert A1 - Gaedke, Ursula A1 - Weisse, Thomas T1 - Lake morphometry and wind exposure may shape the plankton community structure in acidic mining lakes N2 - Acidic mining lakes (pH <3) are specific habitats exhibiting particular chemical and biological characteristics. The species richness is low and mixotrophy and omnivory are common features of the plankton food web in such lakes. The plankton community structure of mining lakes of different morphometry and mixing type but similar chemical characteristics (Lake 130, Germany and Lake Langau, Austria) was investigated. The focus was laid on the species composition, the trophic relationship between the phago-mixotrophic flagellate Ochromonas sp. and bacteria and the formation of a deep chlorophyll maximum along a vertical pH-gradient. The shallow wind-exposed Lake 130 exhibited a higher species richness than Lake Langau. This increase in species richness was made up mainly by mero-planktic species, suggesting a strong benthic/littoral - pelagic coupling. Based on the field data from both lakes, a nonlinear, negative relation between bacteria and Ochromonas biomass was found, suggesting that at an Ochromonas biomass below 50 mu g CL-1. the grazing pressure on bacteria is low and with increasing Ochromonas biomass bacteria decline. Furthermore, in Lake Langau, a prominent deep chlorophyll maximum was found with chlorophyll concentrations ca. 50 times higher than in the epilimnion which was build up by the euglenophyte Lepocinclis sp. We conclude that lake morphometry, and specific abiotic characteristics such as mixing behaviour influence the community structure in these mining lakes. Y1 - 2010 UR - http://www.sciencedirect.com/science/journal/00759511 U6 - https://doi.org/10.1016/j.limno.2009.11.002 SN - 0075-9511 ER -