KEY WORDS: Trematoda, Skrjabinoplagiorchis ondatrae, Troglotrema srebarni, muskrat, Hungary.

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1 Parasit, hung Recovery of Skrjabinoplagiorchis ondatrae (Andiejko, 1965) (Trematoda: Plagiorchiidae) and Troglotrema srebarni Genov, 1964 (Trematoda: Troglotrematidae) from the muskrat in Hungary Dr. Ottó SEY Department of Zoology, Pannon University of Agricultural Science, Georgicon Faculty of Agronomy, Keszthely, Hungary Recovery of Skrjabinoplagiorchis ondatrae (Andrejko, 1965) (Trematoda: Plagiorchiidae) and Troglotrema srebarni Genov, 1964 (Trematoda: Troglotrematidae) from the muskrat in Hungary" - Sey, O. - Parasit, hung., 23: ABSTRACT. Descriptions of Skrjabinoplagiorchis ondatrae and Troglotrema srebarni are given on the basis of specimens collected from muskrats living in the aquatic ecosystems of Lake Fertő and Lake Balaton. KEY WORDS: Trematoda, Skrjabinoplagiorchis ondatrae, Troglotrema srebarni, muskrat, Hungary. The American muskrat (Muridae: Ondatra zibethicus Linné, 1766) is a mammal widely distributed in its homeland, the North American continent. As a fur-bearing animal, it has been introduced to several Eurasian countries since the beginning of the present century. This prolific species, notorious for its migratory habits and excellent acclimatization, soon established itself in Bohemia (DOBRIS 1905) and spread to the neighboring countries as well. The muskrats settled in Hungary are descendants of the Bohemian stock. The first specimens were captured in 1914 on the banks of the river Lajta (Németjárfalu, 1914) and within a few years they spread all over the country. The North American origin of the muskrat, its remarkable distribution, semi-aquatic way of life, and the circumstance that its parasitic fauna has been subjected to investigation in almost all countries where the species occurs, offer every facility for studies aimed at answering the question what modifications in parasitism are likely to occur subsequent to changes in the host's habitat.

2 MATERIAL AND METHODS In the period between 1962 and 1989 more than 200 muskrats were examined for helminth parasites (185 specimens from Fertőrákos, Lake Fertő and 17 specimens from Keszthely, Lake Balaton). The hosts were captured by various techniques and methods and dead animals were dissected in fresh condition. After removal from the organs in question, the flukes were fixed in 70 % alcohol and whole mounts were stained in carmine. RESULTS Skrjabinoplagiorchis ondatrae (Andrejko, 1965) (Fig. 1) Description Body medium in size, elongate oval in form, mm long and mm wide. Cuticle with small spines along its length. Oral sucker terminal by mm in size, pharynx by mm in size; oesophagus absent; caeca in lateral field, extending to posterior extremity of body. Ventral sucker by mm in size. Testes lying symmetrically in posterior part of body; they are elongated oval; right testis by mm, left testis by mm in size. Vas deferens running medially. Cirrus pouch well developed, arcuate in position in middle region in front of ventral sucker, by 0.20 mm in size. It contains oval and convoluted seminal vesicle and pars prostatica. Ovary entire, on right side to ventral sucker, measuring by mm. Uterus strongly developed, situated in area between ventral sucker and caecal ends, mostly intertesticular. Uterine eggs oval, by mm with miracidia. Genital pore left to median line, in front of ventral sucker. Vitellaria strongly developed, follicules small, extending along both sides from pharynx to extremity of body; anteriorly they penetrate to median fields. Excretory pore at tip of posterior extremity. Host: Ondatra zibethicus Habitat: liver (biliary duct). Distribution: Moldavia, Hungary (Lake Fertő, Lake Balaton). Specimens: (4 expl.) Department of Zoology, University of Agricultural Science, Keszthely, Hungary. Troglotrema srebarni Genov, 1964 (Fig. 2) Description Body small, pyriform, mm long and mm wide at level of ventral sucker. Cuticle with spines along whole body. Oral sucker by mm in size; pharynx by mm in size; oesophagus absent, caeca in lateral fields, extending to posterior extremity. Ventral sucker in anterior half of body, median, by mm in size. Testes lying symmetrically or slightly diagonal. Right testis by mm, left testis by mm in size.

3 0.25 mm Fig 1: Skrjabinoplagiorchis ondatrae (Andrejko, 1965)

4 Cirrus pouch arcuated, S-shaped, by mm, containing seminal vesicle, ejaculatory duct and an unarmed cirrus. Ovary oval, left to ventral sucker, measuring by mm. Uterus relatively short, situated mainly between ventral sucker and testes and somewhat pretesticularly. Genital opening median, right behind ventral sucker. Eggs in utero measuring by mm. Vitellaria strongly developed, in lateral fields along caeca from ventral sucker to posterior extremity. Host: Ondatra zibethicus Habitat: in cyst attached to duodenum. Distribution: Bulgaria, Hungary (Lake Balaton, Lake Fertő). Specimens: (2 expl.) Department of Zoology, University of Agricultural Science, Keszthely, Hungary mrn Fig 2: Troglotrema srebarni Genov, 1964

5 DISCUSSION The genus Skrjabinoplanorchis was described by PETROV and MERKUSCHEVA (1963) in the U.S.S.R. and now it comprises six species: S. vigisi PETROV et MERKUSCHEVA, 1963; S. morosovi VARENOV, 1965; S. dogieli SEMENOV, 1966; S. obensis FEDEROV, 1976; S. skrjabini (KADENAZII, 1960); and S. ondatrae (ANDREJKO, 1965). These species are parasitic in the liver (biliary ducts) or in the intestine in various species of small rodents including muskrats. S. ondatrae was described for the first time under the name Plagiorchis ondatrae ANDREJKO, 1965 from rodents including muskrats in Moldavia. It was transferred to the genus Skrjabinoplagiorchis by KRASNOLOBOVA (1977). Our finding is a new locality record, and muskrats have supposedly become parasitized from stocks of small rodents living in their environment. The genus Troglotrema ODHNER, 1914 comprises two species: T. acutum (LEUCKART, 1842), parasitic in the frontal and ethmoidal sinuses of some carnivorous mammals in Europe, and T. srebarni, parasitic in muskrats found in Bulgaria. This is a new locality record and the occurrence of troglotrematid species in muskrat indicates the meat-eating behaviour of the muskrat, provided that T. srebarni has the same lifecycle pattern as T. acutum has. SEY, O.: Skrjabinoplagiorchis ondatrae (Andrejko, 1965) (Trematoda: Plagiorchiidae) és Troglotrema srebarni Genov, 1964 (Trematoda: Troglotrematidae) mételyfajok előfordulása magyarországi pézs mapockokban A Moldáviában 1965-ben leírt S. ondatrae és a Bulgáriában 1964-ben felfedezett T. srebarni mételyfajokat a szerző 200 pézsmapocok egyed parazitológiai vizsgálata alapján a Fertő-tó és a Balaton környékén élő Ondatra populációkban is megtalálta; azok eredeti ábrákkal illusztrált morfológiai jellemzését közli. 37

6 REFERENCES ANDREJKO, O. F. (1965): On the helminth parasites of cricetid (Microtinae) rodents in Moldavia and their role in dispersal of diseases of men and domesticated animals (in Russian). In: Parasites of animals of Moldavia and problems of regional parasitology. - Kishinev "Kártya Moldavenyaske", p FEDOROV, K. P. (1976): New species, Skrjabinoplagiorchis PETROV et MER-KUSCHEVA, 1963 from the liver of the muskrat (in Russian). - New and less known species of the fauna of Siberia, Novosibirsk, 10: GENOV, T. (1964): On the helminthofauna of the muskrat (Ondatra zibethica) in Dobrudja, (in Bulgarian). - Bull. Centr. Helminth. Lab., 9: KADENAZII, A. N. (1960): Pachytrema skrjabini nov. sp. - new trematodes from the souslik (in Russian). - Trudy GELAN, 10: KRASNOLOBOVA, T. A. (1977): On the systematics of the trematode genus Plagiorchis Lühe, 1899 (in Russian). - Trudy GELAN, 27: PETROV, A. M. and MERKUSCHEVA, U. V. (1963): A new trematode from rodents Skrjabinoplagiorchis vigisi gen. nov. sp. nov. (Plagiorchiidae Lühe, 1901) (in Russian). - Gelm. chel., zhiv. rast. borb. s. nimi, K 85-let. akad. K. I. Skrjabina, IND. AN USSR, p SEMENOV, N. N. (1966): A new trematode from the liver of yellow-necked field mouse - Skrjabinoplagiorchis dogieli sp. nov. (in Russian). In: Problems in ecology and parasitology of animals. - Volgogr. ped. inst. Saratov Izd. Saratov Univ., p SEY, O. (1967): Modifications of the American muskrat's (Ondatra zibethica L.) parasitic fauna due to acclimatisation. - Acta Zool. hung., 1_3: VARENOV, I. P. (1965): A new trematode of water vole Skrjabinoplagiorchis morosovi sp. nov. (in Russian) - Uchen, Zap. Gor'k. gos. ne. inst., 56: 3-5. Received: 16 September, 1990 Dr. SEY, O. Department of Zoology Pannon University of Agricultural Science, "Georgicon" Faculty of Agronomy H-8361 Keszthely, Deák Ferenc utca 16. HUNGARY 38