MEXICANA IANNACONI SP. N. (MONOGENEA: ANCYROCEPHALIDAE) PARÁSITO DEL CHIVILICO HAEMULON STEINDACHNERI (JORDAN & GILBERT, 1882) (PERCIFORMES: HAEMULIDAE)DE LA COSTA PERUANA

A new species of Mexicana (Monogenea: Ancyrocephalidae) is described, illustrated and compared with the other four known species of the genus (M. anisotremum, M. atlantica, M. bychowskyi and M. littoralis) from a fish of the Peruvian coast: Mexicana iannaconi n. sp. from the gill of Haemulon steindachneri (Haemulidae). The new species is readily distinguished from all of the congeners recorder by the following characteristics: (1) Testicle entirely bipartite. (2) Copulatory organ, long, winding, with circular sclerotized piece at its base. (3) Lateral vitelline glands bind to the ovary and testicular post region and (4) the characteristics of the sclerotic opisthohaptor parts. Our description of this new species of Monogenea demonstrate and clarifies the taxonomic status of the host (H. steindachneri), being a species in the Pacific while other species is in the Atlantic, finding two different congeneric species of Mexicana, M. iannaconi n. sp. in the Pacific and M. atlantica in the Atlantic. An identification key of the species of the genus Mexicana is provided.