During the last two years I took part in excursions to Dorum and Helgoland in September/October together with a group of future biology teachers from Goethe University Frankfurt. I got particularly interested in hermit crabs and in October 2007 I investigated how hermit crabs choose their shell at the Alfred Wegener Institute (AWI) on Helgoland. The AWI kindly provided me with hermit crabs and empty common whelk shells, since adult hermit crabs with common whelk shells and also empty common whelk shells are difficult to find in the rocky tidelands.
Unfortunately, there is little information in the literature on how hermit crabs choose their housing. It is only reported that they select their housing very carefully and that they analyse it in detail (Eigener 1977, Debelius 2007). The goal of the present study is to observe and understand how hermit crabs select their shell and to determine whether they do this generally in the same way or whether there are differences.
