Giese, Elane G.Pinheiro, Raul Henrique S.Swiderski, ZdzislawMiquel Colomé, Jordi2020-05-222021-01-312020-010932-0113https://hdl.handle.net/2445/161989The ultrastructural characteristics of the mature spermatozoon of the aspidogastrean Rohdella amazonica (Aspidogastridae, Rohdellinae) were studied by means of transmission electron microscopy. The sperm cell shows two axonemes of the 9 + '1' trepaxonematan pattern of Platyhelminthes, parallel cortical microtubules, a well-developed lateral expansion, external ornamentation of the plasma membrane, one mitochondrion, an electron-dense ring, a nucleus and granules of glycogen. The present results were compared with those observed in the aspidogastreans studied to date and in other Platyhelminthes. The lateral expansion and the electron-dense ring are typical characters for aspidogastreans. Although a lateral expansion has been described in other Platyhelminthes such as monogeneans and digeneans, the Aspidogastrea shows a much larger lateral expansion with both peripheral and internal microtubules. The dense ring is observed as a cylinder in a longitudinal view and shows a more granular appearance in sperm cells from the seminal vesicle in comparison to a more electron-dense appearance in sperm cells from the seminal uterine receptacle.8 p.application/pdfeng(c) Springer Verlag, 2020Cèl·lules germinalsParàsitsPlatihelmintsUltraestructura (Biologia)ParasitologiaGerm cellsParasitesPlatyhelminthesUltrastructure (Biology)Parasitologyinfo:eu-repo/semantics/article6913092020-05-22info:eu-repo/semantics/openAccess31760497