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1.
Abstract. An enzootic, Australian, atypical strain of Aeromonas salmonicida isolated from diseased goldfish, Carassius auratus (L.), was inoculated into Atlantic salmon, Salmo salar L., brown trout, S. trutta L., rainbow trout, S. gairdneri Richardson, and brook trout, Salvelinus fontinalis (Mitchill), fingerlings by intraperitoneal injection (i.p.) and by bath challenge, the latter with and without prior abrasion of skin. The 10-day LD50 (i.p.) was estimated to be 7·4 × 10-3 colony forming units (cfu) for Atlantic salmon, 3·0 × 10-2 cfu for brown trout, 3·7 × 102 cfu for brook trout and 6·4 × 103 cfu for rainbow trout. Brown, rainbow and brook trout succumbed to bath challenges with between 105 –106 cfu/ml, developing ulcers of the skin and septicaemia. The organism was trasmitted from inoculated fish to five of 195 within-tank control fish via water and established a carrier state in one of 14 Atlantic salmon. It was concluded that the organism poses a significant threat to the salmonid farming industry and wild salmonid fisheries in Australia. 相似文献
2.
James M. Myers William K. Hershberger Robert N. Iwamoto 《Journal of the World Aquaculture Society》1986,17(1-4):1-7
The induction of tetraploidy was attempted in three intraspecies crosses (autotetraploid) of sal-monid: chinook salmon ( Oncorhynchus tshawytscha ), coho salmon ( O. kisutch ) and rainbow trout ( Salmo gairdneri ), and in the interspecies hybrid (allotetraploid) coho × Atlantic salmon ( Salmo salar ).
Pressure treatments of 6.2 × 104 kPa (9,000 psi) were applied for six minutes at intervals from 50% of the time to cleavage to beyond first cleavage. Analysis of eyed stage embryos via flow cytometry indicated two periods of tetraploid induction existed corresponding to 55–75% and 100–110% of the first cleavage interval (FCI).
The effects of different pressures and the times of application were analyzed in a study with rainbow trout. Treatments of 4.8 × 104 kPa (7,000 psi) for eight minutes, and 5.5 and 6.2 × 104 kPa (8,000 and 9,000 psi) for four minutes, were applied at 65, 78, and 100% FCI. Tetraploids were found in the 5.5 and 6.2 × 104 kPa group treatments only when applied at 65% FCI.
The results indicate that, while tetraploidy is inducible in salmonids, further experimentation is necessary to discern the appropriate time and treatment for optimal tetraploid induction in each species. 相似文献
Pressure treatments of 6.2 × 10
The effects of different pressures and the times of application were analyzed in a study with rainbow trout. Treatments of 4.8 × 10
The results indicate that, while tetraploidy is inducible in salmonids, further experimentation is necessary to discern the appropriate time and treatment for optimal tetraploid induction in each species. 相似文献
3.
Abstract. The pathogenicity of Renibacterium salmoninarum to carp, Cyprinus carpio L., and rainbow trout, Salmo gairdneri Richardson, was investigated. All carp injected with 4·8 × 108 cells/fish, or 4·8 × 107 cells/fish survived for 38 days. R. salmoninarum was isolated from all moribund fish, but not from the kidney of surviving fish, although R. salmoninarum antigen was detected in several of these fish by the dot blot assay. On the other hand, mortality in rainbow trout was 95% in the fish injected with 4·8 × 108 cells/fish, and 15% in those which received 4·8 × 107 cells/fish. R. salmoninarum antigen was detected by the dot blot assay in all surviving rainbow trout. The number of R. salmoninarum cells was immediately decreased by carp or rainbow trout serum, and the serum bactericidal activity of carp was higher than that of rainbow trout. Carp blood leucocytes had higher phagocytic activity than those of rainbow trout. 相似文献
4.
Abstract. Infection trials using two serotypes of VHS viruses (type 1 and 23/75) demonstrated that Atlantic salmon fry were susceptible to the disease when injected intraperitoneally (i.p.) with 103 pfu of virus/fish but resistant to infection by a bath method when exposed for 3 h in water containing 5 × 104 pfu of virus/ml. In the i.p.-infected fish, mortality reached 78 and 67% within 13 days with VHSV1 nad 23/75 serotypes, respectively. High virus yields were recovered from infected fish and virus shedding was demonstrated by the onset of VHS in rainbow trout kept in the outflow water from the aquaria containing infected salmon. Neither mortality nor virus shedding occurred in salmon infected by the water route but virus multiplication was demonstrated in 2 of 60 fish with VHSV1 and 3 of 60 fish with virus 23/75. On day 79 post-infection the sera from surviving salmon of both i.p. and bath infection trials exhibited good neutralizing titres (around 1000) against the homologous viruses. 相似文献
5.
Abstract. An atypical strain of Aeromonas salmonicida was isolated from goldfish. Carassitis auraius L., with cutaneous ulcerativc lesions. Atlantic salmon, Salmo salar L., weighing 30–40 g were challenged parentcrally and by hath immersion with this strain. It was found to be highly virulent in both forms of challenge and was capable of achieving an LD50 of three colony-forming units in parenterally challenged fish. The gross lesions and histopathology of infected fish bore a close resemblance to classical furunculosis in salmonids. Goldfish ulcer disease is endemic to some regions of Australia and represents a potential threat to the emerging salmonid farming industry. 相似文献
6.
Abstract. An epizootic in juvenile turbol reared on a farm located in The Ria de Vigo, Galicia, Northwest Spain, is described. The diseased turbot did not display unusual swimming behavior; the external signs of the disease were abdominal distension and haemorrbagic areas in the mouth. Internal examination of the fist showed an accumulation of reddish fluid in the peritoneal cavity. Microbiological analysis of the diseased fish revealed the presence, in pure culture in all the organs and lesions examined, of a bacterium which was characterized biochemically as Vibrio splendidus biotype I. The virulence tests showed that the V. splendidus biotype I isolate was pathogenic for rainbow trout (LD50 : 2.2 × 104 ) and also for turbot (LD50 : 1.2 × 104 ). The treatment of the fish using flumequine incorporated into the feed was effective in offsetting the mortality rate. 相似文献
7.
A Gregory L A Munro M Snow K L Urquhart A G Murray R S Raynard 《Journal of fish diseases》2009,32(6):481-489
This study investigated infection dynamics of infectious salmon anaemia virus (ISAV) by conducting two experiments to examine minimum infective dose and viral shedding of ISAV. In terms of minimum infective dose, the high variability between replicate tanks and the relatively slow spread of infection through the population at 1 × 101 TCID50 mL−1 indicated this dose is approaching the minimum infective dose for ISAV in seawater salmon populations. A novel qPCR assay incorporating an influenza virus control standard with each seawater sample was developed that enabled the quantity of ISAV shed from infected populations to be estimated in values equivalent to viral titres. Viral shedding was first detected at 7 days post-challenge (5.8 × 10−2 TCID50 mL−1 kg−1 ) and rose to levels above the minimum infective dose (4.2 × 101 TCID50 mL−1 kg−1 ) on day 11 post-challenge, 2 days before mortalities in ISAV inoculated fish started. These results clearly demonstrate that a large viral shedding event occurs before death. Viral titres peaked at 7.0 × 101 TCID50 mL−1 kg−1 15 days post-infection. These data provide important information relevant to the management of ISA. 相似文献
8.
Abstract. Atlantic salmon, Salmo salar L., parr were injected intraperitoneally with different quantities of formalin (37% formaldehyde) following anaesthetization with either benzocaine (ethyl-p-aminobenzoate) or chlorbutol (1,1,1,-trichloro 2-methyl-2-propanol) The LD50 for injected formaldehyde was found to be approximately 50mg kg−1 body weight. The type and concentration of the anaesthetic used did not influence mortality rates. Formalin is commonly used to inactivate microorganisms in vaccines. Doses of formalin which were shown to be toxic in this study are close to those which may be injected into fish as a component of various vaccines against bacterial fish diseases. Hence, the formalin content in fish vaccines may well cause mortality under certain conditions. 相似文献
9.
Abstract. The infectivity of the bacterial fish pathogen Aeromonas salmonicida subsp. salmonicida to Atlantic salmon, Salmo salar L., in sea water was investigated and found to be similar to that reported for fresh water. The minimal infective dose in short duration bath exposures (1–3 days) was 104 colony-forming units (cfu) per ml, while prolonged exposure for three weeks, but not for 1 week, produced infection with 102 cfu/ml. Intragastric intubation of A. salmonicida established infection with doses of >105 cfu. Release of bacteria from dead or morbid infected fish was monitored and found to be in the order of 105 –108 cfu/fish/h. These results emphasize the importance of removing dead fish from farm sites. 相似文献
10.
The use of wrasse as cleaner fish in farming of Atlantic salmon, Salmo salar L., is now widespread in Scotland, Ireland and Norway, but little is known about the susceptibility of these fish to the common pathogens of cage-cultured salmon. The susceptibility of goldsinny wrasse, Ctenolabrus rupestris L., to infectious pancreatic necrosis virus (IPNV) was investigated. Captive-bred C. rupestris were infected with IPNV-Sp (Shetland strain) using a bath challenge method. Two infection doses were used, low (4.1 × 105 pfu mL−−1 ) and high (2.4 × 106 pfu mL−−1 ), with two replicates for each experiment. Bathing times were 1 h for the low dose and 5 h for the high dose. A maximum prevalence of infection (30%) was seen 2 weeks post-infection in replicate 1 of the low dose experiment and was accompanied by low tissue titres. The tissue titres dropped to an undetectable level by 4 weeks post-infection. In the high dose experiment, a high prevalence of infection was seen along with moderate titres in tissues as well as a marked pathological response. Both prevalence and intensity declined rapidly and the fish recovered. In the high dose experiment, faecal titres followed the same pattern as those in the tissues. The implications for the use of wrasse in the farming of Atlantic salmon are discussed. 相似文献
11.
MURIEL COSSARINI-DUNIER 《Journal of fish diseases》1986,9(1):27-33
Abstract. Rainbow trout, Salmo gairdneri Richardson, (average weight 100g) were vaccinated intraperitoneally (i.p.) with Yersinia ruckeri bacterin in saline or in oily adjuvant. Agglutinating antibody kinetics were followed during 445 days before challenge (1.2×107 bacteria i.p.). Fourteen days after challenge 88.5% of the control fish had died while few mortalities were observed with vaccinated fish regardless of their agglutinating titre. Protection against Y. ruckeri does not seem to be due to antibodies. 相似文献
12.
Abstract– Allozyme and other protein loci were examined to study the genetic structure of Portuguese brown trout ( Salmo trutta ) populations. A total of 247 individuals from three tributaries of the Lima hydrological basin and a hatchery, all located in northern Portugal, were analyzed. Four of 22 protein coding loci were found to be polymorphic: CK-A1* , GPI-A2* , MPI-2* and TF* . A new allelc at the latter locus was found in Atlantic populations. The data obtained for Portuguese brown trout were compared with published data for 14 European populations and three hatchery stocks. Six polymorphic loci (CK-A1* , GPI-A2* , GPI-B2* , LDH-C* , ME* and MPI-2* ) were used in a cluster analysis. This showed the similarity of Portuguese natural populations and northern Iberian populations and that Portuguese hatchery fish have an autochthonous origin, distinct from that of other Atlantic hatchery stocks. 相似文献
13.
K Pedersen H F Skall A M Lassen-Nielsen L Bjerrum N J Olesen 《Journal of fish diseases》2009,32(5):465-472
A selection of 16 field isolates of Photobacterium damselae from marine rainbow trout farms in Denmark was subjected to phenotypic and genotypic characterization and pathogenicity to fish. All isolates belonged to the subspecies damselae , being positive for haemolysis, motility and urease. There were considerable differences in haemolytic properties, some isolates presenting a broad zone of haemolysis and others only a narrow zone. Pulsed-field gel electrophoresis revealed a high diversity indicating that P. damselae subsp. damselae is an opportunistic, not clonal pathogen in Danish marine rainbow trout. Virulence of the strains to rainbow trout was highly variable with LD50 values ranging from 3.9 × 103 to 1.5 × 108 cfu at 20 °C. The virulence was significantly higher at 20 °C than at 13 °C. The strains with the strongest haemolytic properties were the most virulent suggesting a strong involvement of haemolysin in the pathogenesis. The pathological changes were consistent with a bacterial septicaemia and the haemorrhages were more pronounced than for most other bacterial infections. 相似文献
14.
Abstract – The swimming performance of wild and hatchery-reared smolts of two salmonid species was investigated. Wild Atlantic salmon smolts (WS) and brown trout smolts (WT) of equal size were caught in fish traps during migration. Hatchery-reared smolts of both species (HS and HT for salmon and trout respectively) were first generation offspring from wild broodstock. The swimming performance of individual smolts from the four groups (WS, HS, WT, HT) was tested three consecutive times using a swimming flume with water flowing at a start rate of 0.16 m·s−1 and a constant acceleration rate of 0.167 cm·s−2 (10 cm·s−1 ·min−1 ). Wild caught smolts of both species performed significantly better than those reared in hatchery conditions. The WS group were observed to maintain an average swimming speed ( U burst ) that was 30% faster than the HS group, whereas the wild trout smolts were superior to HT by approximately 25%. Repeated measures revealed species-specific exhaustion patterns. Brown trout smolts maintained consecutive U burst indicating significant stamina compared with Atlantic salmon smolts that were found to be exhausted by the initial trial. 相似文献
15.
Abstract. A semi-quantitative technique of assessing trout, Salmo trutta L., and juvenile Atlantic salmon, Salmo salar L., stocks in small rivers is described and evaluated against a commonly used quantitative method. The results indicate that for 0+ and >0+ juvenile salmon and trout a log10 n+1 transformed linear regression accounted for between 68.6% and 90.2% of the total variance in the relationship between the semi-quantitative and the quantitative result. The use of a categorization system is recommended and the applicability of the technique to an extensive juvenile salmonid monitoring programme is described. 相似文献
16.
The present study evaluates if abdominal dis-tension caused by a water-filled stomach in seawater farmed rainbow trout, Oncorhynchus mykiss (Walbaum), and Atlantic salmon, Salmo salar L., could be provoked experimentally by live chilling in sea water (0.5 °C). Fifty rainbow trout and 50 salmon were visually classified, either as normal or suffering from the condition. Prior to chilling, no rainbow trout or salmon suffered from a water-filled stomach. During chilling, 25% of the rainbow trout and 2.5% of the salmon developed water-filled stomach. Affected rainbow trout had significantly higher blood plasma osmolality and significantly lower body weight than normal trout. The frequency of trout with a water-filled stomach increased significantly with increasing chilling time and increasing plasma osmolality. The regression coefficients revealed that the proportion of affected rainbow trout in-creased by 0.82% h−1 of chilling and by 0.46% per unit increase in mosmol L−1. The present study revealed that abdominal distension in seawater farmed rainbow trout was far more severe than in Atlantic salmon and could be provoked experimentally by osmoregulatory stress. This is consistent with the observation that water-filled stomach appear only occasionally in seawater farmed Atlantic salmon. 相似文献
17.
A. M. BAYA A. E. TORANZO B. LUPIANI Y. SANTOS F. M. HETRICK 《Journal of fish diseases》1992,15(1):15-26
Abstract. Characterization of a red pigmented enterobacterium isolated from natural population of white perch, Morone americanus (Gmelin), during the course of a bacteriological survey in the Back River (Baltimore, Maryland, USA) indicated that the bacterium belonged to the species Serratia marcescents. The virulence properties of this isolate (RB 469), studied in comparison with the reference strain of S. marcescens ATCC 1800 and S. plymuthica K1R, revealed that all the strains were highly pathogenic for fish with LD50 s raging from 5 × 103 to 1 × 105 . Similarly, te extracellular products (ECP) from the three isolates were lethal for fish (LD50 ranging from 0·22 to 4·8 μg protein g-1 fish). However, only ECP from strains with strong proteolytic activity (the white perch isolate and S. plymuthica ) were cytotoxic for both in fish and homoiothermic cell cultures and both activities were completely destroyed by heating at 100°C for 10min. In contrast, only the two S. marcescens strains which possessed phospholipase active were pathogenic for mice and produced enterotoxins. None of the Serratia strains displayed dermonecrotic factor in rabbits. All these lindings indicate that a direct relationship between eytotoxicity and virulence cannot be established. 相似文献
18.
Abstract. Viral haemorrhagic septicaemia (VHS) is reported for the first time in sea-water cultured rainbow trout. Heavy mortalities with typical signs and lesions A VHS virus (serotype 1) was isolated from the diseased fish. The mortalities were caused only by the VHS virus and 80 days post transfer of trout to sea-water the mortalities reached 85%, of the initial population.
The disease was experimentally transmitted to rainbow trout, both in sea-water 3·104 pfu/ml of virus or by intramuscular injection of various doses of VHS1 (7·101 7·104 or 7·104 pfu per fish). Death occurred in all infected groups and started earlier in sea-water. Typical signs of VHS were observed in moribund fish. Viral multiplication was demonstrated to have occurred in fish organs. 相似文献
The disease was experimentally transmitted to rainbow trout, both in sea-water 3·10
19.
Abstract– Downstrcam displacement of salmonid fry due to flow increase, from 12–15 m3 /s to >100 m3 s , was documented in the river Suldalslåen, Western Norway. In May only fry of brown trout ( Sulmo trutta ) occurred in the drift, while from the beginning of June only newly emerged Atlantic salmon ( Sulmo sular ) were found. The maximum number of Atlantic salmon fry drifting during a single day was estimated to be 17 000 individual. Their density in the drift was higher during the night than during the day, and their appearance in the drift coincided with the predicted period of emergence. Total brown trout numbers in the drift were estimated to vary between 4000 and 16 000 per day. Fry displaced downstream from the lowermost part of the river were lost from the population. The total losses were estimated to be between 75 000 and 100 000 Atlantic salmon fry which represents between 5.6 and 11.1%) of juvenile mortality during the first year of life. 相似文献
20.
The in vitro metabolism of 14 CD3 and 3 H25OHD3 was investigated in different tissues from Atlantic salmon Salmo salar , Atlantic mackerel Scomber scombrus , Atlantic halibut Hippoglossus hippoglossus and Atlantic cod Gadus morhua . The tissues analysed were liver, kidney, head kidney, gills, spleen and intestine. The metabolites were extracted in methanol–chloroform and separated by normal-phase high-pressure liquid chromatography (HPLC) followed by scintillation counting. Identification of the metabolites was by comigration with standards on normal and reversed-phase HPLC systems and by protein-binding assays. All tissues from all species analysed produced hydroxylated derivatives identified as 25OHD3 , 24,25(OH)2 D3 and 1,25(OH)2 D3 . In addition, some unidentified derivatives were recorded, one probably being 25,26(OH)2 D3 . Organs producing great amounts of one metabolite also produced considerable amounts of the other possible derivatives, suggesting a lower degree of specificity in fish organs than in human organs. The predominating metabolite was 24,25(OH)2 D3 in all organs from salmon and mackerel during incubation with 14 CD3 and within most organs from all species during 3 H25OHD3 incubation. The latter observation probably results from the need for decreasing rather than increasing the calcium absorption in these species, which live at least some periods of life in a marine environment. 相似文献