Oligapta manteri sp. nov. is described from the gills of Hemirhamphus sp. from Noumea, New Caledonia. It differs from the existing species in the genus, O. oligapta because the atrial spines are restricted to a circle of 16, the penis is armed with 47 anteriorly directed, pear-like spines, and the sclerotization of the copulation canal is conical. Pseudothoracocotyle scomberomori sp. nov. is described from the gills of Scomberomorus commersoni from Heron Island, and Green Island, Queensland, Australia. The new species differs from the existing species in the genus, P. ovalis, because the genital pore is not sclerotized, there are two pores to the copulation canal, and the clamps are more numerous and larger.