Bradymyces oncorhynchi is a poorly known melanised fungal species that has been isolated only from a hyperaemic focus near the enlarged spleen of a rainbow trout. Although the pathogenicity of this species to fish is suspected, it has not been fully confirmed. Four laboratory experiments were conducted to test the effect of the fungus on the health of rainbow trout fingerlings. Mycelia were cultivated under different conditions to increase inoculum variability and to test the impact of the conditions on the pathogenicity. The inoculum was subsequently administered by the intraperitoneal route. The clinical manifestations, gross pathological lesions and histopathological changes were identical in all experimental groups, i.e. lethargy, inappetence, anorexia, weight reduction, pale gills, full-thickness ulceration of the abdominal wall, muscle atrophy, haemorrhagic or pale liver, fat-altered pyloric region with haemorrhages, enlarged spleen, haemorrhagic ascites, systemic granulomatous lesions with the presence of melanised hyphae (phaeohyphomycosis), multifocal granulomatous hepatitis, perivascular lymphocytic infiltration, vacuolation of hepatocytes and vacuolation of the kidney tubule epithelium. No statistically significant differences were found in the survival of the fish with respect to experimental settings. The survival period ranged between 3 and 135 days.
In this study, the effects of the eye fluke Diplostomum pseudospathaceum (Trematoda) infection on over-winter survival of young-of-the-year (YOY) European bitterling Rhodeus amarus (Cyprinidae) were examined between September 2010 and April 2011. The fish were reared in semi-natural conditions to ensure that results were not confounded by other parasite infections. The cumulative mortality of R. amarus from November until April was significantly higher in D. pseudospathaceum-infected fish (57·3%) compared to controls (42·1%). Infection of the parental generation did not have any effect on the mortality of juveniles. The results indicate that D. pseudospathaceum infection increases over-winter mortality of YOY R. amarus. The possible mechanisms causing mortality are discussed.
- MeSH
- Cyprinidae parazitologie MeSH
- nemoci ryb mortalita parazitologie MeSH
- roční období MeSH
- Trematoda * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Body condition and parasite abundance were examined in two size classes of European bitterling Rhodeus amarus during the first overwintering period in two seasons (2007-2008 and 2009-2010). Body condition of large fish did not change during winter, and increased significantly in March. From November to February, small fish showed a decreasing trend in condition. Despite a significant increase in March condition of small fish only reached the same level as before winter. Total parasite abundance increased significantly in winter in both fish size classes, reflecting a seasonal increase in monogenean infection. Large fish were parasitized significantly more than small fish during winter, but only in small fish was a negative correlation between parasite infection and condition found and a significant decrease in parasite abundance recorded after wintering, indicating mortality of heavily infected individuals with low condition during the winter. A trend for higher overwinter mortality in small fish was found under semi-experimental conditions. The decrease in condition during the winter period in small fish may reflect faster energy depletion generally expected in smaller individuals. The results indicate that parasite infection may contribute to the overwinter mortality of 0+ year R. amarus, with a stronger effect in smaller individuals.
- MeSH
- analýza přežití MeSH
- Cyprinidae MeSH
- hustota populace MeSH
- infekce červy třídy Trematoda mortalita patologie MeSH
- interakce hostitele a parazita MeSH
- nemoci ryb mortalita patologie MeSH
- roční období * MeSH
- tělesná konstituce fyziologie MeSH
- Trematoda fyziologie MeSH
- velikost těla fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- chov MeSH
- druhová specificita MeSH
- Herpesviridae fyziologie MeSH
- herpetické infekce genetika mortalita veterinární MeSH
- kapři genetika virologie MeSH
- náchylnost k nemoci veterinární MeSH
- nemoci ryb genetika mortalita virologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
From 22 May to 10 June 2011 massive mortality of Prussian carp Carassius gibelio was observed in alluvial Lake Řehacˇka close to the Elbe River in the Czech Republic. More than 1400 kg of dead fish were collected and no other fish species were affected. Further molecular and cytogenetic investigation of fish (n = 232) revealed that the Rˇehacˇka population of Prussian carp consisted exclusively of gynogenetic triploid females. The causative agent was identified by means of molecular and electron microscopy as a herpesviral hematopoietic necrosis virus (Cyprinid herpesvirus 2, CyHV-2). This is the first report of CyHV-2 from the Czech Republic and the second finding worldwide of CyHV-2 causing mass mortality of C. gibelio. Some other localities in the upper Elbe River basin where C. gibelio was affected are also noted. We assume that the massive wave of deaths of all female gynogenetic Prussian carp can be attributed to limited genetic variation and the favourable conditions for development of viral disease.
- MeSH
- genetická predispozice k nemoci MeSH
- Herpesviridae klasifikace MeSH
- herpetické infekce epidemiologie mortalita veterinární virologie MeSH
- jezera MeSH
- kapři genetika MeSH
- nemoci ryb epidemiologie mortalita MeSH
- ploidie MeSH
- řeky MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Gyrodactylus pisculentus sp. n. is described from the head, body and fins of the northern pipefish, Syngnathus fuscus Storer (Syngnathidae) from the environs of Woods Hole, Massachusetts, USA. The new species is compared with Gyrodactylus shorti and Gyrodactylus syngnathi, species previously recorded from pipefish in the United States and Norway, respectively. Gyrodactylus pisculentus was frequently associated with mortality of northern pipefish held in quarantine at the Woods Hole Science Aquarium during 2002-2005. The clinical account of the infections and treatment protocols are presented.
- MeSH
- fylogeneze MeSH
- infekce červy třídy Trematoda mortalita veterinární MeSH
- nemoci ryb mortalita parazitologie MeSH
- ryby parazitologie MeSH
- Trematoda anatomie a histologie klasifikace MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Geografické názvy
- Massachusetts MeSH
