Dr. Kassai Tibor - Dr. Murai Éva szerk.: Parasitologia Hungarica 6. (Budapest, 1973)
ted dorsoventrally and take the lateral position only by mechanical effect (Pig. 9.) Certain differences may be seen also in the shape of the ovary of the two species. The ovary of B. phoxini is elongated, and medially constricted, whilst that of B. gowkongensis shows - at least in some of the preparations - also an expressed medial thickening besides the two lateral swellings. Our morphological data are supported by epidemiological observations as well. B . phoxini is considered an endemic parasite living exclusively in Phoxinus phoxinus, and before the introduction of plant-eating fishes it considerably infected Phoxinus phoxinus living at their present place of occurrence. B . gowkongensis spread very quickly all over the country after its importation ,and was detected from Cyprinus carpio, Ctenopharyngodon idellus ,furthermore also from Hypophthalmichthys nobilis, Barbus barbus, Scardinius erythrophthalmus and Rutilus rutilus (BUZA et al. 1970). Despite the few years of its occurrence in Europe, many reports have been published on B. gowkongensis, and the name of this parasite became well-known. Most of the publications dealt with the spreading of the worm and the pathology of infection. The validity of the species was contended only by DUBININA (1962, 1971). However, since OTTE et al. (1972) identified this parasite as B . acheilognathi Yamaguti, 1934, the problem should be clarified whether B. gowkongensis Yeh, 1955, B. Opsariichthydis Yamaguti, 1934 (preferred by DUBIN INA) and B. acheilognathi Yamaguti, 1934, can or cannot be considered as distinct species. Our investigations,and in particular those concerning B. phoxini. Molnár, 1968, suggest that care should be taken in synonymization. The clarification of these problems can be made only by a thorough examination and comparison of worms from the original Par East hosts. Pending these studies, the parasite imported to Europe should be referred to as B. gowkongensis . 106
