@article{WeisseLaufensteinWeithoff2013,
  author    = {Weisse, Thomas and Laufenstein, Nicole and Weithoff, Guntram},
  title     = {Multiple environmental stressors confine the ecological niche of the rotifer Cephalodella acidophila},
  series = {Freshwater biology},
  volume    = {58},
  journal   = {Freshwater biology},
  number    = {5},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0046-5070},
  doi       = {10.1111/fwb.12104},
  pages     = {1008 -- 1015},
  year      = {2013},
  abstract  = {1The planktonic food web in extremely acidic mining lakes is restricted to a few species that are either acidophilic or acidotolerant. Common metazoans inhabiting acidic mining lakes with a pH below 3 include rotifers in the genera Cephalodella and Elosa. 2The life history response of Cephalodella acidophila to three environmental key factors, pH (2, 3.5, 5.0 and 7.0), temperature (10, 17.5 and 25 degrees C) and food concentration (10000, 35000 and 50000algal cells per mL), was investigated in a full factorial design using life-table experiments. 3The effect of each of the three environmental variables investigated on the rotifer life cycle parameters (life span, fecundity and population growth rate) differed. C.acidophila is a stenoecious species with a pH optimum in the range 34 and a comparably high food threshold. Combining the laboratory results with field data, we conclude that C.acidophila is severely growth limited in its natural habitat. However, low pH alone is not harmful as long as temperatures are moderate to warm and food is abundant. 4The population of C.acidophila in the field is maintained mainly due to release from competitors and predators.},
  language  = {en}
}
@article{LischkeWeithoffWickhametal.2016,
  author    = {Lischke, Betty and Weithoff, Guntram and Wickham, Stephen A. and Attermeyer, Katrin and Großart, Hans-Peter and Scharnweber, Inga Kristin and Hilt, Sabine and Gaedke, Ursula},
  title     = {Large biomass of small feeders: ciliates may dominate herbivory in eutrophic lakes},
  series = {Journal of plankton research},
  volume    = {38},
  journal   = {Journal of plankton research},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0142-7873},
  doi       = {10.1093/plankt/fbv102},
  pages     = {2 -- 15},
  year      = {2016},
  abstract  = {The importance of ciliates as herbivores and in biogeochemical cycles is increasingly recognized. An opportunity to observe the potential consequences of zooplankton dominated by ciliates arose when winter fish kills resulted in strong suppression of crustaceans by young planktivorous fish in two shallow lakes. On an annual average, ciliates made up 38-76\% of the total zooplankton biomass in both lakes during two subsequent years. Consequently, ciliate biomass and their estimated grazing potential were extremely high compared with other lakes of various trophic states and depths. Grazing estimates based on abundance and size suggest that ciliates should have cleared the water column of small (<5 mu m) and intermediate (5-50 mu m) sized phytoplankton more than once a day. Especially, small feeders within the ciliates were important, likely exerting a strong top-down control on small phytoplankton. Particle-attached bacteria were presumably strongly suppressed by intermediate-sized ciliate feeders. In contrast to other lakes, large phytoplankton was proportionately very abundant. The phytoplankton community had a high evenness, which may be attributed to the feeding by numerous fast growing and selective ciliate species. Our study highlights ciliates as an important trophic link and adds to the growing awareness of the role of winter processes for plankton dynamics.},
  language  = {en}
}
@article{ParaskevopoulouTiedemannWeithoff2018,
  author    = {Paraskevopoulou, Sofia and Tiedemann, Ralph and Weithoff, Guntram},
  title     = {Differential response to heat stress among evolutionary lineages of an aquatic invertebrate species complex},
  series = {Biology letters},
  volume    = {14},
  journal   = {Biology letters},
  number    = {11},
  publisher = {Royal Society},
  address   = {London},
  issn      = {1744-9561},
  doi       = {10.1098/rsbl.2018.0498},
  pages     = {5},
  year      = {2018},
  abstract  = {Under global warming scenarios, rising temperatures can constitute heat stress to which species may respond differentially. Within a described species, knowledge on cryptic diversity is of further relevance, as different lineages/cryptic species may respond differentially to environmental change. The Brachionus calyciflorus species complex (Rotifera), which was recently described using integrative taxonomy, is an essential component of aquatic ecosystems. Here, we tested the hypothesis that these (formerly cryptic) species differ in their heat tolerance. We assigned 47 clones with nuclear ITS1 (nuITS1) and mitochondrial COI (mtCOI) markers to evolutionary lineages, now named B. calyciflorus sensu stricto (s.s.) and B. fernandoi. We selected 15 representative clones and assessed their heat tolerance as a bi-dimensional phenotypic trait affected by both the intensity and duration of heat stress. We found two distinct groups, with B. calyciflorus s.s. clones having higher heat tolerance than the novel species B. fernandoi. This apparent temperature specialization among former cryptic species underscores the necessity of a sound species delimitation and assignment, when organismal responses to environmental changes are investigated.},
  language  = {en}
}
@misc{DragoWeithoff2021,
  author    = {Drago, Claudia and Weithoff, Guntram},
  title     = {Variable Fitness Response of Two Rotifer Species Exposed to Microplastics Particles},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1248},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-55261},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-552615},
  pages     = {13},
  year      = {2021},
  abstract  = {Plastic pollution is an increasing environmental problem, but a comprehensive understanding of its effect in the environment is still missing. The wide variety of size, shape, and polymer composition of plastics impedes an adequate risk assessment. We investigated the effect of differently sized polystyrene beads (1-, 3-, 6-µm; PS) and polyamide fragments (5-25 µm, PA) and non-plastics items such as silica beads (3-µm, SiO2) on the population growth, reproduction (egg ratio), and survival of two common aquatic micro invertebrates: the rotifer species Brachionus calyciflorus and Brachionus fernandoi. The MPs were combined with food quantity, limiting and saturating food concentration, and with food of different quality. We found variable fitness responses with a significant effect of 3-µm PS on the population growth rate in both rotifer species with respect to food quantity. An interaction between the food quality and the MPs treatments was found in the reproduction of B. calyciflorus. PA and SiO2 beads had no effect on fitness response. This study provides further evidence of the indirect effect of MPs in planktonic rotifers and the importance of testing different environmental conditions that could influence the effect of MPs.},
  language  = {en}
}
@article{DragoWeithoff2021,
  author    = {Drago, Claudia and Weithoff, Guntram},
  title     = {Variable Fitness Response of Two Rotifer Species Exposed to Microplastics Particles},
  series = {Toxics},
  volume    = {9},
  journal   = {Toxics},
  number    = {11},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2305-6304},
  doi       = {10.3390/toxics9110305},
  pages     = {13},
  year      = {2021},
  abstract  = {Plastic pollution is an increasing environmental problem, but a comprehensive understanding of its effect in the environment is still missing. The wide variety of size, shape, and polymer composition of plastics impedes an adequate risk assessment. We investigated the effect of differently sized polystyrene beads (1-, 3-, 6-µm; PS) and polyamide fragments (5-25 µm, PA) and non-plastics items such as silica beads (3-µm, SiO2) on the population growth, reproduction (egg ratio), and survival of two common aquatic micro invertebrates: the rotifer species Brachionus calyciflorus and Brachionus fernandoi. The MPs were combined with food quantity, limiting and saturating food concentration, and with food of different quality. We found variable fitness responses with a significant effect of 3-µm PS on the population growth rate in both rotifer species with respect to food quantity. An interaction between the food quality and the MPs treatments was found in the reproduction of B. calyciflorus. PA and SiO2 beads had no effect on fitness response. This study provides further evidence of the indirect effect of MPs in planktonic rotifers and the importance of testing different environmental conditions that could influence the effect of MPs.},
  language  = {en}
}