摘要:

AbstractA cutaneous ulcerative disease (red spot) in sea mullet,Mugil cephalusL., from the Clarence River, New South Wales, Australia, was first reported in 1972. In this study, reports of disease outbreaks have been compared with rainfall and river flow records for the period from 1972 to 1988. Detailed disease prevalence, rainfall, river flow and water quality data were compared for the period from 1985 to 1988. Significant correlations between weekly rainfall in the lower catchment and the prevalence of early stage lesions have been found. Progression to later stages of the disease occurred after rainfall and high river flows, which also caused rapid changes in various water‐quality characteristics such as salinity, temperature, dissolved oxygen, pH and turbidity. Organochlorine insecticide residues were not found to be associated with the disease in this area. The rainfall record since 1902 does not explain the absence of earlier reports of the disease. It is postulated that extensive structural developments for flood mitigation purposes and the increase in agricultural cultivation in the lower Clarence catchment during the last 20 years may be factors associated with the onset of the early stage of red spot disease. Fish in this early stage of the disease may then develop dermal ulcers under the stressful river conditions typically present during the autumn (high rainfall) seaso

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01236.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractScanning electron micrographs of halibut eggs with an epiflora dominated byFlexibactersp., showed ulcerations colonized by large numbers of bacteria. The chorion was dissolved in most ulcerations and the zona radiata was severely damaged. Infection experiments showed that exposure to these bacteria caused high mortalities at the late egg stage, hatching and the early yolk sac stage. Eggs exposed to three differentVibriospp. showed different mortality patterns, with low mortality at hatching, followed by a continuous high mortality throughout the yolk sac stage. Mortality in the uninfected control group was low throughout the experiment. Transmission electron microscopy of theVibrio‐infected larvae showed bacteria present in the gill, heart and frontal yolk sac region

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01237.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractBath treatments with mebendazolc (MBZ) are commonly used for control of pseudodactylogyrosis in intensive eel eulture systems in Europe. To assess the potential for selection of drug‐resistant gill parasites in these systems, the authors have conducted a number of sub‐therapeutic treatments of an anthelmintic naive population of Pseudodactylogyrus bini (Kikuchi, 1929) Gussev, 1965, and P. anguillae (Yin et Sproson, 1948) Gussev, 1965, with different eoncentrations of MBZ. Parasite populations subtherapeutically treated seven times during a 7‐month period with 0.05 and 0.005 mg MBZI−1developed a high and low relative resistance to MBZ, respectively. It was shown that low temperatures decreased the effect of MBZ. In addition, the benzimidazoles albendazole and triclabendazole produced a comparatively lower parasiticidal effect, and it is suggested that treatments at low temperatures or with low effect bcnzimidazoles will increase the risk of selection of drug‐resistant gill parasites in

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01238.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractA description is given of cardiac and skeletal myopathy in Atlantic salmon, Sahno salar L., during pancreas disease. Post‐smous in two farms were sampled weekly from April to Oetober. Panereas disease was diagnosed at 9 and 13 weeks after sea transfer on the two farms, respeetively. Myodegenerative lesions were observed in the hearts of fish with hoth normal and diseased panereas. The prevalenee of heart lesions was highest amongst fish affeetcd with panereas disease. Skeletal myopathy of red fibres was observed only in fish in the recovery and chronic phases of disease, whereas white fibre changes were observed in fish with normal pancreas and fish affeetcd with panereas diseas

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01239.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe monogeneanAnoplodiscus cirrtisspiralisinfects the fins and nares of snapper,Pagrus auratus(Bloch&Schneider). The epidermis beneath the haptor in both microhabitats is eroded and the parasite attaches to the basement membrane by an adhesive secretion. Captive snapper suffered fin damage through high levels of infection by this parasite. Laboratory experiments showedA. cirrusspiralisto be adversely affected by reduced salinity and killed within 1 h by diluted sea water of<5%0 salinity.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01240.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractA Total of 355 strains of fish‐pathogenic bacteria, includingVibrio anguillarum, Aeromonas hydrophila, A. Caviae, Pseudomonas fluorescensandP. putida, were examined for the presence of hydroxamate‐or phenolate‐type siderophores. These strains were isolated from diseased rainbow trout,Oncorhynchus mykiss(Walbaum), from fish farms in the Baltic Sea off the coast of the former German Democratic Republic. The production of siderophores was demonstrated in bioassays and siderophore‐pattern analysed using several indicator strains. All strains tested grew under conditions of iron limitation. The strains of Vibrionacease produced at least a hydorxamate‐type siderophore detected by the bioassay withA. flavercensJG‐9. Only a fewV. anguillarum, but 50% ofA. hydrophilaproduced a phenolate‐type siderophore. Seventy percent ofV. anguillarum, 33% ifA. hydrophila, 40% ofA. caviae, 53% ofP. fluorescensand 50% ofP. putidapromoted the growth of the indication strainS. typhimuriumSR 1001, which can use iron by 2,3‐dihydroxybenxoic acid. The pseudomonads tested produced either hydroxamate‐ or phenolate‐type si

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01241.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe abundances ofAeromonas salmonicidasubsp.salmonicidain the water and in the surface microlayer was studied during the initial phase of a cohabitant infection experiment with Atlantic salmon,Salmo salarL., smolt.Aeromonas salmonicidawas detected in the water samples only until the intraperitoneally infected smolt were dead and had been removed. In the lipid rich surface microlayer,A. salmonicidawas detected in high concentrations from the day of the first fish mortality and throughout the rest of the experiment. The significance of the high cell surface hydrophobicity is discussed as a possible reason for enrichment ofA. salmonicidaat the air‐water interfac

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01242.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01243.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01244.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1992.tb01245.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY