This is a mature Daphnia magna imaged under a microscope at 20x magnification. The photo was taken at the end of the 21 day exposure to sunscreen so that we could measure its body length.

A team from the University of Birmingham in the UK looked at the effects of microplastics and PFAS (per- and polyfluoroalkyl substances) on Daphnia magna water fleas, both separately and mixed ...