Of the four species of Octolasmis, O. cor occurred only in Scylla serrata. Octolasmis Stella and O. tridens preferred invariably Charybdis cruciata, C. natator and Podophthalmus vigil. Medium and larger sized crabs harboured more number of epizoites except in few cases where the reverse was encountered. Moulting, growth and the subsequent increase in the size of the gill area of the hosts appear to influence the abundance of barnacles. No significance was observed between the variations in the numbers of epizoic barnacles and right and left side gills of the host crabs.

Ventral face of the gills were infested heavily with the epizoic barnacles than the dorsal, anterior and posterior faces. Gills 2-6 showed concentration of barnacles, particularly gills 3-5.