The ultrastructure of the spermatozoon in Pisione remota (Annelida: Polychaeta) and its transformation in the receptaculum seminis.
The spermatozoon of Pisione remota and its transformation after transmission into the female are unique within Polychaeta. Most prominent organelles of the rod-shaped aflagellate gamete in the male are an elongate nucleus formed like a canoe, a parallel arranged vacuole-like structure with a peripheral network of cisternae, and mitochondria and lamellar bodies on both ends of the cell. In the female the vacuole-like structure detaches from the nucleus and is obviously phagocytosed by a receptacle cell. The nucleus is largely expanded. The cytoplasmic sheath of the sperm differentiates to form a system of pseudopod-like projections that envelop the apical projections of the receptacle cells. The structures and their transformations are considered to be related to a long-term storage of the sperm in the female.
Westheide
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Universität Osnabrück, Fachbereich Biologie/Chemie, FRG.
D000818:Animals; D000845:Annelida / Q000648:ultrastructure; D002454:Cell Differentiation; D005260:Female; D005836:Genitalia, Female / Q000502:physiology / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology / Q000648:ultrastructure*