Host-parasite relation between the shore crab Carcinus maenas and Sacculina carcini (Rhizocephala): Identification and characterization of a specific fraction correlated with parasitism

Two protein fractions have been revealed in the blood of infested crabs. These fractions do not occur in healthy animals. Their relations are analyzed. Both present the same electrophoretic mobility and have common antigenic determinants. They are characterized in relation to the major serologic components of the hemolymph.