The life cycle of troglotrema acutum
Vogel, H.; Voelker, J.
Tropenmedizin und Parasitologie 29(4): 385-405
1978
ISSN/ISBN: 0303-4208 PMID: 741501 Document Number: 126413
The life cycle of T. acutum (F.S. Leuck., 1842), a trematode living in the paranasal sinuses of the polecat (Mustela putorius) and causing destruction of the skull bones, was elucidated. Encysted metacercariae isolated from the musculature of grass frogs (Rana temporaria) caught in middle and southern Germany were fed to ferrets (M. putorius furo) and domestic cats. In 3 ferrets, adults of T. acutum were found at autopsy in the nasal sinuses, accompanied by lesions of the adjacent bones. Groups of Bythinella dunkeri and B. alta, small prosobranchiate snails which occur in cool well waters were exposed to miracidia hatched from Troglotrema eggs. At a water temperature of 10-13.degree. C, it took 9 mo. until the 1st cercariae emerged. In the musculature of a grass frog from northern Germany, exposed to these cercariae, metacercariae developed which were indistinguishable from those observed in naturally infected frogs. The morphology of the eggs, rediae, cercariae and metacercariae of T. acutum are described. The cercaria is characterized by a stumpy tail which at the posterior end is covered with minute spines, a stylet, 12 penetration glands, a Y-shaped excretory vesicle with an epithelial wall and a group of radially arranged glands which open into a ventral groove at the posterior part of the body. Since a gland complex of corresponding structure is a characteristic feature of the microcercous Xiphidiocercariae of the gerna Nanophyetus, Sellacotyle, Skrjabinophyetus and Nephrotrema, a close relationship of the genus Troglotrema with the above mentioned genera is assumed. Assumption of a close relationship between Paragonimus and Troglotrema, is not supported. The metacercaria has numerous unicellular glands which open near the oral sucker. Corresponding cephalic glands were detected earlier in adults of T. acutum and they are considered responsible for bone destruction.