The present study was carried out in the Laboratory of Parasitology and Aquaculture Health of the Peruvian Amazon Research Institute (IIAP), in a period of six months, from May 28 to October 20; The purpose of this research was to make the taxonomic identification of species of parasitic monogenoids of the gills of Pterophyllum scalare "angelfish"; and Cupid Biotodoma “pretty face”. The fish were acquired through fishermen from the Itaya River, specifically from the community of San Andrés, a place that is located in the District of Belén, Province of Maynas, department of Loreto, Peru. Those who were entrusted with the fishing for their subsequent sale of the captured specimens. 30 specimens of Pterophyllum scalare and 30 of Biotodoma cupido were acquired, making a total of 60 individuals. The fish were transferred in plastic bags to the Aquaculture Parasitology and Health Laborat...