Plastic caps, fragments of glass bottle necks or light bulb sockets are some of the most common temporary homes described among the hundreds of land hermit crabs (species of the genus Coebonita) observed by naturalists and analyzed in a study led by experts from the universities of Warsaw and Poznan (Poland) whose results have been published in the journal Science of The Total Environment. As the authors highlight in the headline of the scientific article, plastic is the most common material in the new survival shells of these crustaceans. The other notable element is that, obviously, plastic waste – and other devices – are distinctive of the so-called geological epoch or era of the Anthropocene.
The authors indicate that, according to their calculations, “ten of the sixteen species of land hermit crabs in the world use some type of residual material of human origin, mainly plastics, as shelter.” “This unusual behavior is observed in all tropical regions of the Earth where these species of crabs live,” explains Professor Marta Szulkin, from the Institute of Evolutionary Biology, Faculty of Biology, Center for Biological and Chemical Research, University of Warsaw. , Poland.
One of the novelties of the study is the citizen participation and use of research methods associated with iEcology, with various online data sources as a tool in ecological research. The contribution of data and images from various points on the planet has made it possible to confirm and analyze the appearance of a new behavior in terrestrial hermit crabs. Volunteer naturalists and professional scientists agree that “most of the animals observed resort to plastic because it is the most frequent and persistent residual material in their now contaminated habitats,” notes the University of Warsaw.
“Hermit crabs need to protect their soft abdomen. Generally, until now, they always did it by hiding in the shells left by dead crustaceans, changing as the crustacean grows,” Marta Szulkin recalled.
The scientists analyzed data and photographs of 386 hermit crabs from the family Coenobitidae using artificial shells made from plastic, metal and glass waste. Among the factors that influence the choice of these homes, researchers highlight: sexual selection, the weight of plastics, odorous stimuli and the possibility of camouflage in contaminated environments.
In the course of future research, scientists aim to refine the explanation of this behavior and its impact on the evolution of hermit crabs.
“These analyzes will deepen our understanding of the consequences of plastic pollution in marine ecosystems, as well as the evolution of species in the context of the new evolutionary pressures associated with the Anthropocene,” said researcher Marta Szulkin.