We studied the response of the heterotrophic flagellate (HF) community to the combined impact of warming and ocean acidification in a mesocosm experiment with a plankton community from the western Baltic Sea. We performed a quantitative analysis of the response at the level of total biomass and size classes and a semi-quantitative one at the level of individual taxa. Total biomass of HF was significantly lower under higher temperatures while there was no significant effect of CO2. The mean biomass of the picoflagellates did not respond to temperature while the three nanoflagellate size classes (class limits 3, 5, 8, 15μm) responded negatively to warming while not responding to CO2. The taxon-level results indicate that heterotrophic flagellates do not form a homogenous trophic guild, as often assumed in pelagic food web studies. Instead, the heterotrophic flagellates formed a "food web within the food web". There was a pronounced succession of flagellates leading from a dominance of bacterivores and colloidal matter feeders before the phytoplankton bloom to omnivorous feeders preying upon phytoplankton and heterotrophic flagellates during and after the bloom. This complex intraguild predation patterns probably dampened the response to experimental treatments.
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http://dx.doi.org/10.1016/j.protis.2016.06.004 | DOI Listing |
Eur J Protistol
October 2024
Department of Botany, Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic; Třeboň Experimental Garden and Gene Pool Collections, Institute of Botany of the CAS, Třeboň, Czech Republic.
This review aims to compile sparse information on the ecology of freshwater heterotrophic euglenoids and synthesize the main phenomena and hypotheses from published results. Apparently, heterotrophic euglenoids play a very important role in the nutrient flow of water ecosystems and are irreplaceable heterotrophic contributors in benthic communities, as their total biomass is by far the largest among heterotrophic flagellates. Even though they are obviously a very crucial part of the diversity of freshwater heterotrophic protists, and likely the most represented (in terms of biovolume) group of heterotrophic flagellates, there have been only a few attempts to elucidate their ecological preferences, roles, niches, and importance.
View Article and Find Full Text PDFCurr Biol
January 2025
Ecologie Systématique Evolution, CNRS, Université Paris-Saclay, AgroParisTech, 91190 Gif-sur-Yvette, France. Electronic address:
Eukaryotes evolved from prokaryotic predecessors in the early Proterozoic and radiated from their already complex last common ancestor, diversifying into several supergroups with unresolved deep evolutionary connections. They evolved extremely diverse lifestyles, playing crucial roles in the carbon cycle. Heterotrophic flagellates are arguably the most diverse eukaryotes and often occupy basal positions in phylogenetic trees.
View Article and Find Full Text PDFISME J
January 2024
Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, 37005, České Budějovice, Czech Republic.
PeerJ
September 2024
Department Biodiversity, University of Duisburg-Essen, Essen, North Rhine Westphalia, Germany.
The increasing frequency and intensity of heatwaves driven by climate change significantly impact microbial communities in freshwater habitats, particularly eukaryotic microorganisms. Heterotrophic nanoflagellates are important bacterivorous grazers and play a crucial role in aquatic food webs, influencing the morphological and taxonomic structure of bacterial communities. This study investigates the responses of three flagellate taxa to heatwave conditions through single-strain and mixed culture experiments, highlighting the impact of both biotic and abiotic factors on functional redundancy between morphologically similar protist species under thermal stress.
View Article and Find Full Text PDFMicrobiome
September 2024
Institut de Ciències del Mar (ICM), CSIC, Barcelona, Catalonia, Spain.
Background: The backbone of the eukaryotic tree of life contains taxa only found in molecular surveys, of which we still have a limited understanding. Such is the case of Picozoa, an enigmatic lineage of heterotrophic picoeukaryotes within the supergroup Archaeplastida, which has emerged as a significant component of marine microbial planktonic communities. To enhance our understanding of the diversity, distribution, and ecology of Picozoa, we conduct a comprehensive assessment at different levels, from assemblages to taxa, employing phylogenetic analysis, species distribution modeling, and ecological niche characterization.
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