Occupancy of gastropod shells by the hermit Crab Clibanarius erythropus (Crustacea, Anomura) inhabiting the Mediterranean Sea coast of Libya

The present study deals with the use of gastropod shells by the hermit crab Clibanarius erythropus (Decapoda: Anomura) inhabiting the Mediterranean Sea coast of Libya. Specimens of the crab were collected on 21 June 2014 from Misrata city, western Mediterranean Sea coast of Libya. A total of 260 individuals were collected which included 63 males (24.23%), 74 non-ovigerous females (28.46%) and 123 ovigerous females (47.31%). The study revealed that the crab occupied 11 gastropod shell species. The most common occupied shell species was Pisania striata (36%) followed by Cerithium lividulum (26%), Cerithium vulgatum (15%) and Phorcus turbinatus (8%). Shell utilization patterns appear to be determined by respective sex, size of hermit crabs and shell species. Male C. erythropus occupies the relatively large and heavy gastropod shell species (Pisania striata and Phorcus turbinatus). Small crabs occupy relatively larger shell species than large crabs. Positive relationships were recorded between the variables of the shells occupied and the hermit crabs size variables. The present study referred that the shell length and shell aperture width were the most important choice factors for the studied hermit crab.