Data from: Microplastics disrupt hermit crab shell selection

Microplastics (plastics < 5 mm) are a potential threat to marine
biodiversity. However, the effects of microplastic pollution on animal
behaviour and cognition are poorly understood. We used shell selection in
common European hermit crabs (Pagurus bernhardus) as a model to test
whether microplastic exposure impacts the essential survival behaviours of
contacting, investigating, and entering an optimal shell. We kept 64
female hermit crabs in tanks containing either polyethylene spheres (n =
35) or no plastic (n = 29) for five days. We then transferred subjects
into suboptimal shells and placed them in an observation tank with an
optimal alternative shell. Plastic-exposed hermit crabs showed impaired
shell selection: they were less likely than controls to contact optimal
shells or enter them. They also took longer to contact and enter the
optimal shell. Plastic exposure did not affect time spent investigating
the optimal shell. These results indicate that microplastics impair
cognition (information-gathering and processing), disrupting an essential
survival behaviour in hermit crabs.