As part of a biodiversity study in northwestern Hungary, we conducted a parasitological survey of small mammals. In both common shrews (Sorex araneus Linnaeus) and pygmy shrews (Sorex minutus Linnaeus), we found myxospores of a species of Soricimyxum Prunescu, Prunescu, Pucek et Lom, 2007 (Myxosporea) and plasmodia in the bile ducts within the liver. Spores from both species of shrewswere morphologically and morphometrically indistinguishable, but differed in their SSU rRNA gene sequences by 3.3%. We identified spores and developmental stages from the common shrew as Soricimyxum fegati Prunescu, Prunescu, Pucek et Lom, 2007, based on morphometric data and DNA sequence similarity. Spores from the pygmy shrew were only 96.7% similar to S. fegati, hence we identified them as a novel myxosporean Soricimyxum minuti sp. n. This is only the second myxosporean parasite species described from mammals., Csaba Székely, Gábor Cech, Stephen D. Atkinson, Kálmán Molnár, László Egyed, András Gubányi., and Obsahuje bibliografii
The development of Myxobolus dispar Thélohan, 1895, a myxosporean parasite of the gills of common carp (Cyprinus carpio L.) was studied in experimentally infected oligochaetes Tubifex tubifex Muller. After infection of uninfected tubificids with mature spores of M. dispar, development of actinosporean stages was first observed light microscopically 21 days after initial exposure. In histological sections, early pansporocysts were located in the gut epithelium of experimental oligochaetes, while advanced stages occupied mostly the outer layers of the gut and the coelozoic space. Mature pansporocysts, each containing 8 raabeia spores, appeared 199 days after initial exposure. Following damage of the intestinal wall and rupture of the pansporocysts, free actinosporean stages were found in the gut lumen of the oligochaetes. Actinospores of hi. dispar emerged from the worms after 217 days of intra-oligochaete development. They were floating in the water and showed a unique raabeia form. Each raabeia spore had three pyriform polar capsules and a cylindrical-shaped sporoplasm with approximately 32 secondary cells. The spore body joined the three caudal projections without a style. Caudal projections were bifurcated at the end and the two main branches had further small bifurcations. The total length of the raabeia spore was approximately 158 pm. The prevalence of infection in 240 experimentally infected Tubifex specimens was 99.2%. No infection was found in the control oligochaetes.
The swimbladder parasite Anguillicola crassus Kuwahara, Niimi et Itagaki, 1974 (Nematoda: Dracunculoidea) is a well-known pathogenic parasite of the Japanese and European eels. Numerous studies on the life cycle of the parasite have revealed the involvement of a copepod or an ostracod intermediate host and a fish paratenic host, in which the third-stage larvae (Lj) infective to the eel develop. The present study comprised infection experiments with the larvae of A. crassus. These experiments can be divided into three groups: (1) experimental reproduction of the parasite's life cycle via copepod intermediate hosts and fish paratenic hosts, (2) infection of another potential paratenic host with third-stage larvae of A. crassus collected from a paratenic host; (3) study of the ability of larvae damaged by paratenic hosts to infect the final host, the eel. Infection experiments have revealed that larvae which are still viable but have become encapsulated as a result of the host reaction mounted against them by cyprinid paratenic hosts (bleak, Alhumus alhumus) have lost their ability to infect the final host, the eel. At the same time, experimental infection of the eel with larvae derived from other paratenic fish hosts (river goby, Neogobius fluviati-lis: ruffe, Gymnocephalus cemua) showing no or only weak host reaction proved to be successful.
During health surveys of 7- to 9-week-old goldfish (Carassius auratus L.) fingerlings in a fish farm near Budapest, Hungary, myxosporean plasmodia were observed on the fins. Plasmodia were most frequently found at the intersegmental joints of the finrays. Spores of Myxobolus diversus Nie et Li, 1973 known from China, were detectable in the mature plasmodia located within the lumen, and less often on the surface, of the cartilaginous finrays. The external wall of the plasmodia was constituted by a capsule formed from a collagenous material identical with the cartilaginous substance of the finrays. Matured plasmodia were filled by spores of 12-14 × 8-9.5 µm in size. The relatively small plasmodia caused only small deformities on the fins. Their importance is, however, not negligible, as in an ornamental fish such as the goldfish even a minor damage of the fins causes a loss of value. Besides a report on the first European occurrence and pathological aspects, a redescription of this parasite of Far-Eastern origin is given.
The infection with Myxobolus intimus Zaika, 1965 in the gills of the roach Rutilus rutilus (L.) from Lake Balaton was recorded in 28 out of the 39 fish examined. Developing and mature plasmodia were detected on the gills exclusively in the spring. The Myxobolus intimus infection was found only in 2- to 3-year-old fish. In histological sections, young plasmodia were found in capillaries of the secondary lamellae. More mature, round plasmodia 0.4-0.6 mm in diameter, deformed the respiratory lamellae. The intraoligochaete development of M. intimus was studied in experimentally infected oligochaetes. In two experiments, uninfected Tubifex tubifex Müller and Limnodrilus hoffmeisteri (Claparède) were exposed to mature myxospores of M. intimus. In both experiments, typical triactinospores developed in T. tubifex specimens but no infection was found in L. hoffmeisteri. In semithin sections, developmental stages, pansporocysts and actinospores, were found within the proliferated gut epithelium of T. tubifex. Triactinospores were first released from oligochaetes 37 and 58 days after initial exposure in the two experiments, respectively. Each triactinospore had three pyriform polar capsules and a cylindrical sporoplasm with 32 secondary cells. The spore body joined the 3 caudal projections with a moderately long style.
A new nematode genus and species, Lucionema balatonense gen. et sp. п., is described from the swimbladder of the European pikeperch, Stizostedion lucioperca (L.), from Lake Balaton in Hungary; a new dracunculoid family Lucionematidae fam. n. is established to accommodate it. The hitherto monotypie family Lucionematidae shows affinities with the families Skrja-billanidae and Daniconematidae, differing from them mainly in having simple oesophagus without external oesophageal glands and the vulva situated near the middle of body; from the first family also in the absence of the buccal capsule and the bursa-like caudal alae in the male. The genus Lucionema gen. n. is characterized mainly by the presence of 8 cephalic papillae in two circlets, absence of spicules, presence of the copulatory plate, only 2 pairs of postanal papillae in the male, and by the distal part of the monodelphic uterus forming a posteriorly directed coil. The body length of L. balatonense females is 1074-1782 pm, that of the only available male 770 pm. A key to the families of the Dracunculoidea is presented.
During a regular veterinary inspection of fishes from Lake Balaton, Hungary, echinostomatid metacercariae (Digenea), with collar spines characteristic of species of the genera Petasiger Dietz, 1909 and Paryphostomum Dietz, 1909, were found in the lateral line scales of a roach Rutilus rutilus (Linnaeus), an apparently unique site. In a subsequent examination of 586 fishes from 20 different species, similar infections were found in 11 species. The infection was virtually restricted to the lateral line scales, other scales being infected only incidentally. These encysted metacercariae had 27 collar spines, including eight larger angle spines and 19 smaller dorsal spines arranged in two rows. Two types of metacercarial cyst were found. One type had a cyst diameter of 138-171 µm × 105-120 µm and three central dorsal spines that were larger than the remainder and tended to resemble the angle spines. The second type of metacercarial cyst had a diameter of 128-157 µm × 105-115 µm and all 19 dorsal spines of the metacercaria were of a similar size. ITS sequences of the second type of metacercaria exhibited a 100% similarity to sequences of two adult Petasiger phalacrocoracis (Yamaguti, 1939) specimens collected from the gut of Phalacrocorax carbo (Linnaeus) in Hungary and to P. phalacrocoracis deposited in the GenBank database. Sequences obtained from two metacercariae of the first type showed a 2.8-2.9 % difference from sequences of the second type of metacercaria and from those of adult specimens of P. phalacrocoracis from cormorants. Based on these results, the second type metacercaria is considered to be a larval stage of P. phalacrocoracis, but the identity of the first type is uncertain. The unusual location of these metacercariae in the lateral line scales is discussed in relation to their transmission., Kálmán Molnár, David I. Gibson, Gábor Cech, Melitta Papp, Petra Deák-Paulus, Lajos Juhász, Norbert Tóth, Csaba Székely., and Obsahuje bibliografii