Cover Picture and Issue Information

This month’s cover shows the ciliate protist Paramecium caudatum . Protist species like this are commonly found in aquatic habitats and offer a unique study system to test ecologicaland evolutionary concepts. The protist was isolated from a natural pond and subsequently used for microcosm experiments, which have a long tradition for testing ecological and evolutionary concepts. In the accompanying review, Altermatt et al. describe a wide range of available techniques to use this and many other protists species to conduct microcosm experiments. The article gives detailed protocols of available techniques with a focus on modern, high‐frequency and high‐throughput measurements, and outlines how such microcosm experiments may be used to address a wide range of questions. Photo credit: © Regula Illi and Florian Altermatt. [Correction added on 09 August, 2021, after first online publication, cover legend added.]