The objective of this research work was the taxonomic identification of the Calophysus macropterus "mota" parasites and to determine the parasitic indices in fish grown in ponds in the San Martín region. The work was carried out at the Centro de Investigaciones “Carlos Miguel Castañeda Ruiz”, of the Instituto de Investigaciones de la Amazonía Peruana (IIAP) - San Martín Region, between April-October 2017. The fish were extracted weekly with a trawl net to later carry out the respective necropsy in the laboratory. A total of 30 specimens were analyzed by sacrificing them with a stylet at the height of the cephalic region, according to Eiras, 2003. The external and internal organs were separated to be observed in search of parasites, which were placed separately on microscope slides to be identified, according to taxonomic keys of Thatcher 2006. The parasitic fauna consisted of mon...