摘要:

Abstract.Unfertilized, water‐hardened eggs, obtained from a coho salmon,Oncor‐hynchus kisutch(Walbaum), with coelomic fluid containing large enough numbers of the kidney disease bacterium,Renibacterium salmoninarum, to make the fluid cloudy (∼4 × 109cells/ml), were examined by cultural and histological methods to determine (a) whether an earlier finding of the pathogen in coho eggs could be corroborated, and (b) whether iodine (500 mg/l, in the form of povidone‐iodine) was as effective at ridding them of the intra‐ovum pathogen as it was at freeing them of the extra‐ovum pathogen. The results confirmed that the pathogen does indeed occur within the egg (11–6%‐15‐l % of the eggs were infected in this manner), and suggested a location in the yolk for the pathogen. The findings also indicated that while iodine was very effective in killing the pathogen on the surface of the eggs it was completely ineffective in reducing the prevalence of the intra‐ovum infections. The results point out the need for a method for treating eggs internally and confirm the inadvisability of using eggs from salmonids with c

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00921.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.Populations of postlarval, juvenile and adult Kuruma prawns,Penaeus japonicusBate, have been affected by an unusual proliferative condition of the midgut and ventral nerve cord. Animals affected with this gut and nerve syndrome have been observed from various shrimp systems in Hawaii, including high density tanks and raceways, low density ponds, and adult broodstock held in a maturation system. Affected shrimp ranged in age from ∼20‐day‐old postlarvae of ∼0.02g average weight to adult shrimp of ∼ 60 g average weight. The principal lesions observed in affected animals were a hypertrophy of the anterior midgut mucosal epithelium basement membrane (BM) and a hyperplasia of the epineurium that covers the ventral nerve cord and segmental ganglia in the gnathothorax. There seemed to be a positive correlation between increased thickness of the BM and disease, and possibly a relationship between ataxia and lethargy and the degree of hyperplasia of the e

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00922.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.A disease of the vertebral column is described in three adult wild‐caughtLates calcarifer(Bloch) from the Northern Territory, Australia. It is characterized by the deposition of bone in the intervertebral space thus fusing the vertebrae, and the development of a thick gelatinous mass of loose connective tissue around the affected part of the vertebral column. Though aClostridiumsp. was isolated from one fish, it was not thought to be the primary caus

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00923.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.Two groups of rainbow trout fingerlings were exposed for 90 days to 0.2 and 0.4 mg/1 of un‐ionized ammonia, respectively. Several fish exposed to the higher concentration soon developed clinical signs suggestive of a neurological dysfunction but subsequently recovered. No lesion attributable to ammonia was seen in the gills of any of the fish. This raises questions about the precise role of ammonia in the production of gill diseases in intensively cultured trou

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00924.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.Proliferative kidney disease (PKD) was diagnosed in rainbow trout,Salmo gairdneriRichardson, at the Hagerman, Idaho, State Fish Hatchery. Wild fish from Riley Creek, one of the hatchery water supplies, were infected with PKD organisms. Clinical signs, gross pathology and histopathology of affected fish were typical of those reported for PKD in salmonids from European hatcheries. In addition to lesions normally seen, we observed a severe vasculitis and occlusion of renal and hepatic vessels. Ultrastructure of the PKD organism and possible inclusion body production sites are described. The disease outbreak was complicated by the presence of other infectious diseases. This is the first recorded outbreak of PKD in North America.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00925.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.A systemic infection by the microsporidanLomasp. became epizootic and resulted in 10% mortality of the population of 337 869 juvenile chinook salmon,Oncorhynchus tshawytscha(Walbaum), from Crooked Creek, Alaska, at Fort Richardson Hatchery, Anchorage, Alaska in the spring of 1980. The microsporidan, forming xenoparasitic cysts (xenomas) of the cell‐hypertrophy tumour type, was found in the gills, arteries, bulbus arteriosus, pseudobranch, choroid gland and kidney. Individual spores were found in cartilage, musculature, liver, arteries, kidney, choroid gland, bulbus arteriosus, ventricle and atrium. Tissue alterations included inflammation, necrosis, and occlusion of arteries; degeneration and necrosis of cartilage and musculature of the tail and head; pericarditis of the bulbus arteriosus; and hyperplasia of heart tissues. Severe infections could impair swimming efficiency, reduce growth rate, and increase mortality after release due to starvation and predation. This represents the first report of microsporidiosis in hatchery‐reared chinook salmon caused byLom

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00926.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00927.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00928.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00929.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY