The orderly vacancy chain that Lewis and Rotjan observed is called a synchronous vacancy chain, which is
different from an asynchronous vacancy chain in which a lone crab
encounters a shell, claims it and leaves behind its old home, which is later seized by a
different crab that never interacts
with the first
animal.
Co-authors Sarah Gall and Richard Thompson, marine biologists at Plymouth University in the United Kingdom, looked in 340
different publications for reports about
animal encounters with marine trash.