Dr. Kassai Tibor - Dr. Murai Éva szerk.: Parasitologia Hungarica 8. (Budapest, 1975)

Histological Examination on the Muscular Organs of Some Amphistomes (Trematoda: Paramphistomata) Dr. Ottó SEY Department of Zoology, University College, Pécs "Histological examination on the muscular organs of some amphistomes (Trematoda: Paramphistomata)" - Sey, O. - Parasit. Hung. 8. 55-59. 1975, ABSTRACT. The paper presents histological characterization of the genital atrium of Chiorchis fabaceus (Diesing, 1836), Gastrodiscus aegyptiacus (Cobbold, 1876) and Stichorchis subtriquetrus (Rud,

, 1814) and all of the three muscular organs (pharynx, genital atrium, acetabulum) of Gastrodiscoides hominis (Lewis et Mc Connel, 1876) and Zygocotyle lunata (Diesing, 1836). The results obtained raise the possibility of designating new types of these organs in the future. Since NÄSMARK's monograph (1937) the gross morphology of paramphistomides have enlarged with histological structure of the muscular organs (pharynx, genital atrium and acetabulum). Histological structure of these organs has proved to be a useful parameter in the species identification. NÄSMARK's investigations (19 37), however, were confined to the species of subfamily Paramphistominae; as regards the rest, only "preliminary notes" have been disclosed with the remark that further details will be published in thte second part of the monograph but it has never been published. We considered that the variability of the histological structure of muscular organs in various species of the family Paramphistomidae warrants further examinations. The results of such studies might throw light on the phylogenetic relationships of this group of helminths. Material and Methods Coir specimens of Gastrodiscus aegyptiacus and Gastrodiscoides hominis were collected in Egypt but the latter were of Indian origin. Chiorchis fabaceus and Zygocotyle lunata were sent to the author from the United States and Stichorchis subtriquetrus from the Soviet Union. Five specimens of each species were embedded in paraffin, sectioned (5-8 p.), stained in haematoxyline and eosin and mounted in Canada balsam. Details of the vas deferens were studied on dissected specimens. Results and Discussion Chiorchis fabaceus Diesing, 1836 (Figs. 1-5) It is the parasite of sirens in North and South America and Africa. The pharynx is of the Microrchis (Fig. 1) and the acetabulum is of the Cladorchis types (Figs. 3 and 4). Structure of these organs was similar to that described by NÄSMARK, A muscle layer with 80-85 units in the dorsal part of the acetabulum was observed (Fig. 5) not mentioned in NÄSMARK's description. The genital opening is fairly small (350-370 u in diameter), genital papilla present having no sphincter papillae (Fig. 2). Radial musculature of the genital atrium is poorly developed, ventral atrium absent. Cirrus pouch present, 550-565 x 250-260 ja in size. Vesicula seminalis externa and interna (the latter inside the cirrus pouch) form several whorls. Prostatic gland cells were not observable. The genital atrium of this species was not typified by NÄSMARK (1937); according to our investigations its structure is the closest to the type of genital atrium having neither genital sphincter nor sphincter papillae (Fig. 2).