| ultrastructure of the ovarian follicles, oviducts and oocytes of gyrocotyle urna (neodermata: gyrocotylidea). | an ultrastructural study of the ovarian follicles and their associated oviducts of the cestode gyrocotyle urna grube et wagener, 1852, a parasite from the spiral valve of the rabbit fish, chimaera monstrosa l., was undertaken. each follicle gives rise to follicular oviduct, which opens into one of the five collecting ducts, through which pass mature oocytes. these collecting ducts open into an ovarian receptacle which, in turn, opens via a muscular sphincter (the oocapt) to the main oviduct. the ... | 2010 | 20941909 |
| investigations on the protonephridial system of post-larval gyrocotyle urna and amphilina foliacea (cestoda). | the gross morphology and ultrastructure of the different parts of the protonephridial system of the monozoic tapeworms gyrocotyle urna and amphilina foliacea are described. the terminal cell in both species has numerous cilia which are interconnected and extend into the lumen of the first canal cell. the filtration area is built up from projections of two cells, the terminal cell and the first canal cell. the first canal cell forms a solid hollow cylinder without a cell gap and a desmosome as fo ... | 1992 | 1639564 |
| the unique ultrastructure of the uterus of the gyrocotylidea poche, 1926 (cestoda) and its phylogenetic implications. | the members of the order gyrocotylidea are monozoic tapeworms and generally considered to be the most primitive group of the cestoda in terms of the evolution of this platyhelminth class. as part of a series of ultrastructural studies on gyrocotyle urna (wagener, 1852), three regions of the uterus were distinguished. the proximal region of the uterus is characterised by underlying perikarya, the presence of septate junctions within the epithelial wall and two types of specialised outer coverings ... | 2009 | 19731092 |
| ultrastructure of the neodermal sclerites of gyrocotyle urna grube and wagener, 1852 (gyrocotylidea, cestoda). | body sclerites of gyrocotyle urna grube and wagener, 1852, parasites of chimaera monstrosa l., were studied by transmission electron microscopy. each sclerite consists of ten to 15 concentric layers varying in electron density and thickness. the sclerites insert in pockets whose epithelia are continuous with the body neodermis but are 14 times thinner. the pocket neodermis bears surface projections with an inner electron-dense cylinder and a small electron-dense cap at their tip. it is surrounde ... | 2009 | 19697062 |
| ultrastructure of the surface structures and secretory glands of the rosette attachment organ of gyrocotyle urna (cestoda:gyrocotylidea). | the surface structures and gland cells of the posterior rosette organ of gyrocotyle urna grube et wagener, 1852, a member of the group presumed to be the most basal of the tapeworms (cestoda: gyrocotylidea), was studied by scanning electron and transmission electron microscopy. surface structures on the outer (oriented away from the intestinal wall) and inner (in contact with the intestinal wall) rosette surfaces differ from each other and represent a transitional form between microvilli and mic ... | 2008 | 19202679 |
| isotopic discrimination of stable isotopes of nitrogen (δ15n) and carbon (δ13c) in a host-specific holocephalan tapeworm. | during the past decade, parasites have been considered important components of their ecosystems since they can modify food-web structures and functioning. one constraint to the inclusion of parasites in food-web models is the scarcity of available information on their feeding habits and host-parasite relationships. the stable isotope approach is suggested as a useful methodology to determine the trophic position and feeding habits of parasites. however, the isotopic approach is limited by the la ... | 2014 | 23452719 |
| ultrastructure of the anterior organ and posterior funnel-shaped canal of gyrocotyle urna wagener, 1852 (cestoda: gyrocotylidea). | using scanning and transmission electron microscopy, ultrastructure of the anterior organ and posterior funnel-shaped canal of gyrocotyle urna wagener, 1852 (cestoda: gyrocotylidea) from ratfish, chimaera monstrosa (holocephali), was studied for the first time. the proper anterior organ is localised at a short distance (about 170 µm) from an apical pore surrounded by a receptor field, whereas its distal end is marked by a muscular sphincter. the tegumental surface of this organ is covered with s ... | 2015 | 26040290 |