Pseudoplatystoma punctifer is a catfish species that occupies the first place in the statistics of fishing landings in the region of Loreto, being of economic importance in the Peruvian Amazonia. As an initiative to know the parasites present in the gills of P. punctifer from the Peruvian Amazonia, a study was carried out with fish collected in the Belén Market, in Loreto-Peru. Specimens were provided between June and October 2018 from local fishermen from the Belén Market, in Loreto-Peru and samples were processed and analyzed in the “Laboratorio de Parasitología y Sanidad Acuícola” from the “Instituto de Investigaciones de la Amazonía Peruana” (IIAP) in Iquitos, Loreto-Peru. The analyzes of the gills revealed the presence of two new species of Monogenoidea: Demidospermus aureagarciae n. sp. and D. doncellae n. sp. These species are unique among congeners by the morphology of the copulatory complex and vagina. Demidospermus aureagarciae n. sp presents a male copulatory organ as a coiled tube, with a complete counterclockwise ring, with dilated base with a developed sclerotized margin, from which a flap projects; a concave accessory piece, with a tapered and curved distal part and a saculiform vaginal vestibule, connected to the vaginal canal. Demidospermus doncellae n. sp. presents a copulatory complex that is an elongated coiled tube, with approximately three clockwise rings, with dilated base with a developed sclerotized margin, from which a flap projects; an accessory piece sheath like, and a sclerotized vagina with dextral position, with saclike vaginal vestibule, connected to an elongated canal.

Pseudoplatystoma punctifer是一种鲶鱼品种，在洛雷托地区渔获量统计中占据首位，在秘鲁亚马逊流域具有重要的经济意义。为了了解来自秘鲁亚马逊流域的P. punctifer鳃中存在的寄生虫，我们对秘鲁洛雷托贝伦市场收集的鱼进行了一项研究。样本于 2018 年 6 月至 10 月期间从秘鲁洛雷托省贝伦市场的当地渔民提供，样本在秘鲁亚马逊研究所 (IIAP) 的“Parasitología y Sanidad Acuícola 实验室”进行处理和分析。位于秘鲁洛雷托省伊基托斯。对鳃的分析揭示了单基因总科的两个新物种的存在： Demidospermus aureagarciae n. sp。和D. doncellae sp。这些物种的交配复合体和阴道的形态在同类中是独一无二的。 Demidospermus aureagarciae n． sp将雄性交配器官呈现为盘绕管，具有完整的逆时针环，具有扩张的基部和发达的硬化边缘，从其突出有瓣；凹形附件件，具有锥形和弯曲的远端部分和与阴道管相连的囊状阴道前庭。 Demidospermus doncellae n． sp。呈现出一个交配复合体，它是一个细长的盘管，具有大约三个顺时针环，具有扩张的基部和发达的硬化边缘，从该管中伸出一个瓣；鞘状附件，以及右侧位置的硬化阴道，具有囊状阴道前庭，与细长的阴道管相连。