BIOLOGICAL OBSERVATIONS ON HETEROSACCUS DOLLFUSI BOSCHMA (CIRRIPEDIA: RHIZOCEPHALA), A PARASITE OF CHARYBDIS LONGICOLLIS LEENE (DECAPODA: BRACHYURA), A LESSEPSIAN MIGRANT TO THE MEDITERRANEAN

Abstract

Since 1993, Heterosaccus dollfusi has been a very common parasite on the crab Charybdis longicollis along the Mediterranean coast of Israel. It accompanied from the Red Sea this Lessepsian migrant crab. The parasite is more common on male than female crabs, where it becomes external on hosts of many sizes shortly after a molt and undergoes characteristic growth stages. The parasite usually causes the complete loss of pleopods in both sexes and a feminine broadening of the abdomen in male crabs. Parasite survival is the same in both sexes of the host. More than one parasite per host is frequent, each probably originating from an individual cypris larva rather than from asexual budding. Hosts with single parasites outlive those with multiple infections.