NOTES ON THE BEHAVIOR OF THE PORTUNID CRAB CHARYBDIS-LONGICOLLIS LEENE PARASITIZED BY THE RHIZOCEPHALAN HETEROSACCUS-DOLLFUSI BOSCHMA

A significant portion of the population of Charybdis longicollis (Deca poda: Portunidae) along the Mediterranean coast of Israel is parasitiz ed by the rhizocephalan Heterosaccus dollfusi. The behaviour of the pa rasitized crabs, in different stages of infection, is examined and com pared with the behaviour of nonparasitized crabs. Locomotion, rest, bo dy-, egg- and parasite-grooming, digging and burying, courtship and ma ting are described qualitatively and analysed quantitatively under sta ndardized conditions. Behaviour patterns of parasitized crabs lacking externae, either immature or scarred, were similar to those of nonpara sitized crabs. The presence of externae was observed to modify digging and to inhibit burying behaviour. The presence of externae induces an imitation of egg-grooming behaviour pattern in both males and females . Externae-bearing crabs engaged in parasite-grooming more intensely t han ovigerous crabs in egg-grooming.