Data from: Do microplastic particles affect Daphnia magna at the morphological, life history and molecular level?

Microplastic particles are ubiquitous not only in marine but also in
freshwater ecosystems. However, the impacts of microplastics, consisting
of a large variety of synthetic polymers, on freshwater organisms remains
poorly understood. We examined the effects of two polymer mixtures on the
morphology, life history and on the molecular level of the waterflea
Daphnia magna (three different clones). Microplastic particles of ~40 µm
were supplied at a low concentration (1% of the food particles) leading to
an average of ~30 particles in the digestive tract which reflects a high
microplastic contamination but still resembles a natural situation.
Neither increased mortality nor changes on the morphological (body length,
width and tail spine length) or reproductive parameters were observed for
adult Daphnia. The analyses of juvenile Daphnia revealed a variety of
small and rather subtle responses of morphological traits (body length,
width and tail spine length). For adult Daphnia, alterations in expression
of genes related to stress responses (i.e. HSP60, HSP70 & GST) as
well as of other genes involved in body function and body composition
(i.e. SERCA) were observed already 48h after exposure. We anticipate that
the adverse effects of microplastic might be influenced by many additional
factors like size, shape, type and even age of the particles and that the
rather weak effects, as detected in a laboratory, may lead to reduced
fitness in a natural multi-stressor environment.