six species of gyliauchenids are reported in this study, five in the genus Gyliauchen and one in Apharyngogyliauchen. G. pomacentri n.sp. is described from a single specimen recovered from one of one Pomacentrus philippinus, G. parapapillatus n.sp. is described from 42 specimens in one of one Siganus virgatus. Gyliauchen zancli n.sp. is described from a single specimen in one of one Zanclus cornutus. Gyliauchen nahaensis Ozaki, 1937 is redescribed from 189 specimens in one of two siganus punctatus and establishes a new locality record, and in one of one zanclas cornutus, a new host record. Gyliauchen sp. is described from two specimens of two of four Siganus spinus.