Multiple environmental stressors confine the ecological niche of the rotifer Cephalodella acidophila

Abstract

The 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.The 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 °C) and food concentration (10 000, 35 000 and 50 000 algal cells per mL), was investigated in a full factorial design using life-table experiments.The 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 3–4 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.The population of C. acidophila in the field is maintained mainly due to release from competitors and predators.

Diapause as escape strategy to exposure to toxicants: response of Brachionus calyciforus to arsenic

“…As cyclically parthenogenetic zooplankters evolve rapidly (Fussmann 2011;Declerck et al 2015), it is plausible to conjecture adaptation of diapause stage production patterns under high heavy metal fluctuations. High heavy metal concentrations are known to affect the rotifer community (Cecchine and Snell 1999;Weisse et al 2013). Additionally, the diapause pattern observed in different organisms as response to arsenic might be a general response to stressors (Aruda et al 2011).…”

“…Additionally, mining operations are intense in the region, mainly focused on copper; these contribute to presence of the metals in the waters (Díaz-Palma et al 2012). Not surprisingly, biodiversity in lakes near mining areas is greatly reduced, and zooplankton community structure shows strong particularities (Weisse et al 2011(Weisse et al , 2013. In past decades, mining and the concomitant arsenic concentration in the environment have been associated with severe damage to human health, especially in rural populations (Naujokas et al 2013;Yañez et al 2015).…”

Functional Ecology of the Ciliate Glaucomides bromelicola, and Comparison with the Sympatric Species Bromeliothrix metopoides

“…However, recent experimental evidence with freshwater ciliates, flagellates, and microeukaryotes revealed that the realized pH niche may be confined to a small range, relative to the fundamental pH assessed in the laboratory under optimized conditions. This is because there is a significant interaction of pH with food and temperature (Moser and Weisse 2011;Weisse 2006;Weisse et al 2002Weisse et al , 2013a. Interaction of pH with food quality was obvious for both ciliate species of this study; the pH niche was narrower and, in the case of G. bromelicola, restricted to the pH range typical of bromeliad reservoirs if bacteria were the only food ( Fig.…”

Rotifers in Lake Orta: a potential ecological and evolutionary model system

“…Lakes at different pH naturally host different communities, with more acidic lakes generally hosting fewer species (Bielanska-Granier, 2001;Weisse et al, 2013). Yet, rotifer communities are known to be present in water bodies with different pH.…”