Limnological response from high-altitude wetlands to the water supply in the Andean Altiplano.

The Andean Altiplano-Puna is located at an elevation of approximately 4000 m.a.s.

Life-history strategies in zooplankton promote coexistence of competitors in extreme environments with high metal content.

The toxicity of pollutants on aquatic communities is determined by the specific sensitivities and by the ecological relationships between species, although the role of ecological interactions on the specific sensitivity to pollutants is complex. We tested the effect of exposure to copper on the life-history strategies of two coexisting rotifer species of the genus Brachionus from Inca-Coya lagoon, an isolated water body located in Atacama Desert. The experiments looked at differences in the response to the stress by chemical pollution mimicking field conditions of copper exposure, levels of food, and salinity, between single-species cultures and coexisting species.

Metal stress in zooplankton diapause production: post-hatching response.

Aquatic organisms commonly respond to harsh conditions by forming diapausing stages, which enable populations to survive adverse periods forming egg banks. Production of diapausing eggs is frequently observed in monogonont rotifers, previously changing from asexual to partial sexual reproduction (mixis). In despite that zooplankton are frequently used in ecotoxicological assessment because of their sensitivity to various toxicants and their important role in the ecosystems, toxicity evaluations often consider the directly exposed population produced by parthenogenetic reproduction, exclusively.