Mammomonogamus spp. are parasites with curious characteristics, such as the “Y” shape that results from male and female maintaining the permanent copulation position and the controversial presence or absence of spicules. These nematodes are hematophagous and cause damage to the upper respiratory tracts of cattle, sheep, goats, deer, wild yaks, and orangutans. Human infection is rare and most cases until now have been in the Caribbean Islands or in Brazil, and mainly in farmworkers but recently there have been reports affecting tourists. In the present work, the parasites were recovered from the laryngopharynx and larynx region of Bubalus bubalis on the island of Marajó, Pará, Brazil. Different microscopy methodologies were applied (bright field, fluorescence, and scanning electron microscopy) to explore the ultrastructural details of the anterior end, genital structures and the host tissue damage caused by the nematodes. The well-developed mouth is an important structure in the identification of these nematodes and used by the parasite to adhere to the host’s tissue. Different methodologies in microscopy and molecular biology contributed to a detailed morphological description and showed the phenotypic position of Mammomonogamus laryngeus. Light and scanning electron microscopy (SEM) showed details of the papillae, amphids, festoons, ribs, and teeth. Fluorescence microscopy enabled a detailed characterization of different structures, such as the bursal rays and SEM enabled the visualization of the specialized features of the cuticle surface in the male and female. Histopathological analyses, cryofracture and environmental SEM experiments of the infected tissues were carried out in order to investigate the lesions resultant from the parasitism. In addition, the parasite couples were submitted to cryofracture and these results revealed details of the reproductive structures of both sexes, including the male spicule.

乳单眼菌属 是具有好奇特征的寄生虫，例如雄性和雌性保持永久性交配位置以及存在或不存在针头引起争议的“ Y”形。这些线虫具有食血性，会对牛，绵羊，山羊，鹿，野牛和猩猩的上呼吸道造成损害。人类感染是罕见的，到目前为止，大多数情况是在加勒比群岛或巴西，主要是在农场工人中，但最近有报告影响游客。在目前的工作中，寄生虫是从水牛（Bubalus bubalis）的喉咽和喉区中回收的。在巴西帕拉的马拉霍岛上。应用了不同的显微镜方法（亮场，荧光和扫描电子显微镜）来探讨线虫引起的前端，生殖器结构和宿主组织损伤的超微结构细节。发达的嘴巴是鉴定这些线虫的重要结构，被寄生虫用来粘附在宿主的组织上。显微镜和分子生物学中的不同方法有助于详细的形态学描述，并显示了乳单眼猴的表型位置。光学和扫描电子显微镜（SEM）显示了乳头，两栖动物，花粉，肋骨和牙齿的细节。荧光显微镜可以对不同结构进行详细的表征，如法线射线和SEM可对雄性和雌性表皮表面的特殊特征进行可视化显示。为了研究由寄生虫引起的病变，进行了被感染组织的组织病理学分析，冷冻断裂和环境SEM实验。此外，这些寄生虫夫妇经受了冷冻破裂，这些结果揭示了包括雄性针刺在内的两性生殖结构的细节。