Cyclocotyla bellones Otto, 1823 is a monogenean characterized by an outstanding way of life. It is a hyper parasite that attaches itself to cymothoid isopods, themselves parasites of the buccal cavity of fishes. Cyclocotyla bellones was found on Ceratothoa parallela (Otto, 1828), an isopod parasite of Boops boops off the Algerian coast. We used integrative taxonomy by combining a morphological description of C. bellones with a molecular analysis carried out on COI mtDNA sequences. We provide, for the first time, molecular barcoding of a hyperparasitic monogenean, the parasitic crustacean host, and the primary fish host. Observation of indigestible haematin, a characteristic of fish blood, in walls of the intestine of C. bellones suggests that C. bellones feeds on fish blood. The body shape of various diclidophorids from fish gills or parasitic isopods was compared; we conclude that the anterior stem of the body of C. bellones is an anatomical adaptation for nutrition of the monogenean on the host fish. >Cyclocotyla bellonesis thus a hyperparasite in terms of location (it dwells on a parasite), but not in terms of nutrition (it does not feed on a parasite but on the primary host).