Dr. Murai Éva szerk.: Parasitologia Hungarica 20. (Budapest, 1987)

Typifying and classifying of the muscular organs of amphistomes (Trematoda: Amphistomida) Dr. Ottó SEY Department of Zoology, Janus Pannonius University, Pécs, Hungary "Typifying and classifying of the muscular organs of amphistomes (Trematoda: Amphistomida). - Sey, O. - Parasit, hung., 20:45-63. 1987. ABSTRACT. The structure of the muscular organs (pharynx, terminal genitalium, acetabulum) of amphistomes is an indispensable means in the modern amphistome diagnosis. A comprehensive survey of the muscular organs revealed 43 types of pharynx, including 13 new, 58 types of terminal genitalium, including nine new and 50 types of acetabulum, including 19 new. Description of the new types and a list of the already known types of the muscular organs are given. KEY WORDS: Amphistomes; types of pharynx, terminal genitalium, acetabulum; classification of the muscular organs. The majority of amphistomes are characterized, among others, by having strongly developed body musculature and by the presence of muscular apparatus around the oral opening (pharynx), muscular elements around the genital pore (terminal genitalium) and a muscular ventral sucker (acetabulum). The latter three organs have usually been called muscular organs. Due to the strongly muscular nature of these organs, their structure can be examined on histological sections. Their specific and diagnostic value, involving structural elements of-these organs, were already recognized in the early stages of studies of amphistomes (FISCHOEDER, 1903; STILES and GOLDBERG ER, 1910; LOOSS, 1912; FUKUI, 1929) but NÄSMARK (19 37) was the first to elaborate a new classification based on the histological structure of the pharynx, the genital atrium (now properly named: terminal genitalium EDUARDO, 1982) and acetabulum in observable sections prepared in median sagittal plane. By revelation of features in the structures of the muscular organs the scope of specific traits has further been enlarged, and the more valuable characters due to their relative constancy have proved to be more reliable than the rather variable gross morphological ones. Detailed examinations were carried out by NÀSMARK (1937) referring to the species of the subfamily Paramphistominae, which mainly includes amphistomes of mammalian hosts. He established a special terminology for designation of types of various muscular organs, characteristic of amphistomes only. The framework outlined by him proved to be a useful means in diagnosing amphistomes originated from whatsoever species of the definitive hosts. Subsequent authors following NÄSMARK's diagnostic principles revealed further new types of these muscular organs, and nowadays we have more information on about 196 of the total sum of 246 amphistome species. Such a survey renders it possible to rearrange all the types previously described on the basis of a general guiding principle. The aim of this paper is to provide a comprehensive survey of the types of muscular organs presently known, and to described the new types discovered.