title: Multiple environmental stressors confine the ecological niche of the rotiferCephalodella 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 generaCephalodellaandElosa. The life history response ofCephalodella acidophilato 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. acidophilais 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 thatC. acidophilais 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 ofC. acidophilain the field is maintained mainly due to release from competitors and predators.
authors.affiliation: Research Institute for Limnology of the University of Innsbruck Mondsee, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Weisse
authors.forename: Nicole
authors.initials: N
authors.lastname: Laufenstein
authors.forename: Guntram
authors.initials: G
authors.lastname: Weithoff
keywords: Cephalodella acidophila; acid lakes; life-table experiments; pH; rotifers