Daphnia species are excellent models for studying mechanisms of adaptation and acclimation to environmental stress as well as the evolution of environmental stress response networks. In an ecological context Daphnia species are critical elements of the food chain in many aquatic ecosystems. They represent a major food source for larval and juvenile fishes. Daphnia pulex and Daphnia magna have circumpolar distribution in freshwater, brackish, and even saline ecosystems and are important for sustaining fish stocks and aquatic ecosystem health on a world-wide scale.

Daphnia pulex and D. magna are easy to culture in the laboratory. Moreover, they are translucent enabling the investigator to non-invasively monitor powerful physiological endpoints such as heart rate. Both species are established models for ecosystem monitoring and bioindication. They are routinely used in ecotoxicological and ecophysiological studies and a wealth of physiological data on both species is available.

Daphnia species reproduce parthenogenetically and clonal lines are easily generated. In addition, resting eggs can be stored for many years. Daphnia have very short generation cycles making powerful genetic and evolutionary studies highly feasible. Both species evolve rapidly and many different conspecific populations that are adapted to specific ecological niches occur in enormously diverse habitats all over the world. They are inhabit freshwater but also salt lakes having salinities greater than seawater. For these reasons, Daphnia are exceptionally well suited for investigating mechanisms of adaptive evolution and gene-environment interactions that drive natural selection and salinity adaptation.

Peptide mass fingerprinting