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Werner, M., 2001. Prevalence of the Parasite Sacculina carrini Thompson 1836 (Crustacea, Rhizocephala) on Its Host Crab Carcinus maenas (L.) on the West Coast of Sweden, University of Gothenburg. Reprinted with permission from Ophelia (2001) 55(2): 101-110 Prevalence of the Parasite Sacculina carrini Thompson 1836 (Crustacea, Rhizocephala) on Its Host Crab Carcinus maenas (L.) on the West Coast of SwedenDuring a three-year field study on the West Coast of Sweden the prevalence of external egg sacs of the parasitic barnacle Sacculina carcini on Carcinus maenas was found to be on average 2.9%. Scars after lost parasites occurred on an additionally 2.6% of the crabs and were found more frequently on male than on female hosts. External parasites were found on crabs at a size of 32 to 66 mm in carapace width. The most sheltered locality with the highest abundance of host crabs also had the highest prevalence of externae and scars. Feminisation of male crabs was found to be a reliable indication of internal S. carcini infection and on average, 2.7% of the male crabs were feminisation without having an externa or a scar. No hyper-feminisation was found in the female crabs. The importance of including internally infected crabs in prevalence data, when estimating the degree of parasitism in the host population, is discussed. Entire Paper |