Echinoplectanum rarum is a species of diplectanid monogenean parasitic on the gills of the leopard coralgrouper, Plectropomus leopardus. It has been described in 2006.This species is very rare and represented only 2% of the specimens of Echinoplectanum spp. found in P. leopardus. This species was distinguished from other species of the same genus by its characteristic ring-shaped sclerotised vagina.