Chela-height vs. body-weight relationships for North Sea hermit crabs (Paguridae)

Biomass determination of hermit crabs is difficult without destroying the gastropod shells of the specimens. To minimize the number of animals destroyed in the process of determining this parameter over time, the chela-height vs. body-weight relationship of each of the three hermit-crab species was recorded in different areas of the North Sea. Linear regression was carried out for the species Pagurus bernhardus, P. pubescens, and P. prideauxi, in order to allow calculations of individual biomass on the basis of the chela height of specimens. No spatial differences in the chela-height vs. body-weight relationship were found for single species, whereas the relationship between the three species differed significantly. Thus, for each species a regression function is given, valid for the whole North Sea, that allows estimations of the body weight of the three hermit-crab species from measuring the chela height alone.