The Distribution of the Barnacle Epizoites, Chelonibita patula (Ranzani) on Blue Swimmer Crab, Portunus pelagicus (Linnaeus, 1758)

The frequency and distribution of barnacle (Chelonibia patula) on blue swimmer crab Portunus pelagicus off Persian Gulf Coasts were studied. A total of 545 crabs were examined and were of the same size range. The carapace width rangof crab werefrom 6.5cm to 16.5cm, carapace length from 4 to 8cm and weighed 80.5g to 220.4g. The barnacles were attached to the carapace, abdomen and walking legs. The distribution, size and abundance of barnacles on the crabs were dependent of the size and sex of the crabs. The large sized crabs had as many barnacles attached to them as small crabs. Female crabs had as many barnacles attached to them as male crabs. There were more barnacles on the dorsal surface of the crabs than on the ventral. The number of barnacles on each crab varied from one to twenty-one. There was no significant difference (p<0.05) in the occurrence of barnacles on crab P. pelagicus. The condition factor was quite low in crab species with range of 1.01 to 8.39 (mean 5.48).