In 2014, infectious spleen and kidney necrosis virus (ISKNV), a member of the genus Megalocytivirus, was detected for the first time in ornamental fish in Germany. Since 2013, angelfish Pterophyllum spp. originating from Colombia have experienced significant epizootics in a number of German retailers' facilities. The diseased fish showed symptoms such as increased ventilation, swollen gills, and ulcerations of the skin. In 2014, diseased angelfish P. altum and platys Xiphophorus maculatus maintained in the same recirculating system were examined. Histopathological lesions included hypertrophic cells, single-cell necrosis, and an inflammatory infiltration of granulocytes, lymphocytes, and macrophages in liver, spleen, and kidney. Transmission electron microscopy revealed the presence of numerous poly gonal viral particles (150 nm in diameter) within the cytoplasm of enlarged cells. A PCR assay for the detection of megalocytiviruses amplified 777 bp of major capsid protein gene that was 100% identical to ISKNV. This is the first report of an ISKNV outbreak in Germany that most probably was introduced by infected angelfish from Colombia. To our knowledge, this is the first report of ISKNV detected in fish imported from South America. Given the lethal nature of megalocytiviruses, proper biosecurity would seem prudent in countries like Germany where these emerging pathogens are not established.
The sturgeon microsatellite LS-39 was ampli®ed across 10 dierent species of Acipenserinae and exhibited the potential to identify the black caviar producer Acipenser stellatus on a genomic DNA level. This was because of a ®xed allele of 111 bp, which was absent in the other species which were investigated. Concerning the source of sturgeon species, LS-39 is the ®rst nuclear marker described to examine black caviar. Furthermore, new light is shed on the controversial ploidy state of sturgeons. The present authors ®ndings at this microsatellite locus support the hypothesis that extant 120 chromosomal species are modern diploids, whereas sturgeons with 240 chromosomes should be considered as modern tetraploids.
-In the context of the European Water Framework Directive, the in-and outflow water quality from 13 German trout farms, rearing mainly rainbow trout (Oncorhynchus mykiss) and using inflow rates between 0.03-0.80 m 3 s −1 , were monitored for point-source pollution. The farms had a significant effect on the effluent quality and macro-invertebrate fauna in adjacent streams (saprobic index based on species assemblage and abundance was 1.56-2.10 upstream of the farms but increased to 2.06-2.37 downstream of the farms). Inflow water quality, type of rearing unit, feeding intensity (amount of feed input in relation to water resources) and effluent treatment method could be used to predict effluent quality by 50 to 88% for most water characteristics. Based on these results, different effluent treatment options were monitored for their treatment performance. Concrete sedimentation basins 11 m × 7 m × 1.2 m and 5.5 m × 3.3 m × 1.5 m (L × W × H), respectively, used for total farm effluent had little or no treatment effects. The micro-screen examined was relatively effective on particulate water components, measured as total phosphorous (TP), biochemical oxygen demand (BOD 5 ), chemical oxygen demand (COD) and total suspended solids (TSS), resulting in treatment efficiencies of 29-53%, which is less than expected from data in the literature. The constructed wetland examined showed the highest treatment efficiency: more than 35% for TP, COD, BOD 5 , TSS and total ammonia nitrogen (TAN). From these results and data from the literature, treatment strategies for trout farm effluents can be developed, depending on the rearing system and production intensity. Key words:Aquaculture ecological impact / Trout farming / Effluent quality / Effluent treatment / Sedimentation basins / Constructed wetlands Résumé -Impact de l'aquaculture des truites sur la qualité de l'eau et les traitements des rejets aquacoles. Dans le contexte de la directive cadre européenne sur l'eau, la qualité de l'eau, en entrée et en sortie, a été suivie sur 13 piscicultures allemandes de truites, élevant principalement des truites arc-en-ciel (Oncorhynchus mykiss) et utilisant des débits d'entrée de 0,03 à 0,80 m 3 s −1 , pour évaluer les sources de pollution. Les piscicultures ont un effet significatif sur la qualité des effluents et la faune de macro-invertébrés des rivières voisines (l'index saprobique, basé sur l'assemblage et l'abondance des espèces, est de 1,56 à 2,10 en amont des piscicultures mais augmente en aval : 2,06 à 2,37). La qualité des entrées d'eau, le type d'unité d'élevage, l'intensité de l'alimentation (quantité de nourriture fournie en relation avec les ressources en eau) et la méthode de traitement des effluents peuvent être utilisés pour prédire leur qualité de 50 à 88 % pour la plupart des caractéristiques de l'eau. D'après ces résultats, les différentes options de traitement sont contrôlées pour leur performance. Des bassins de sédimentation en béton 11 m × 7 m × 1,2 m et 5,5 m × 3,3 m × 1,5 m (longueur × largeur × profondeur...
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