摘要:

Abstract.A detailed histopathological study of naturally occurring and experimentally induced outbreaks of nephrocalcinosis was carried out on rainbow trout from a number of farms.Histopathological effects were confined to the kidney, stomach and skeletal muscle. Lesions of the stomach wall were often found in the absence of renal lesions but muscle lesions were only found in the presence of severe renal damage. It was considered that the calcification was the result of deposition of calcium salts within necrotic tissue, and thus was dystrophic rather than metastatic. Variation between farms was considered to be due to variations in the effects of different aetiological factors in the complex series of physico‐chemical events which appear to induce the conditio

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00134.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.Papillomatosis of the European eelAnguilla anguillaL. occurs predominantly in waters of low to medium salinity (3–20%). Tumour‐bearing eels were kept under laboratory conditions for several weeks in salt concentrations of 8, 15 and 30%. As opposed to those kept in freshwater, the experimental animals showed significant decreases in tumour growth rate. At the same time the tumour tissue underwent a marked redifferentiation, i.e. the originally poorly differentiated neoplastic tissue developed numerous mucous and club cells. The characteristic intercellular spaces of tumorous tissue disappeared with the formation of regular membrane interdigitations between adjacent cells. The nucleus to cytoplasm ratios of the neoplastic cells decreased to one‐third of those of the untreated tumour. These changes resulted in a reversion of the neoplastic tissue to a structural condition essentially similar to that of normal epidermis. After a period of 2 to 3 months an adaptation to the altered salinity of the external medium was evident in that the tumorous tissue began to return to its original

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00135.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.The occurrence of cysts ofHenneguya psomspermicaon a population of perch was studied over a periot of 19 months. Cysts were restricted to the gill filaments although no attempt was made to assess the occurrence of earlier developnental stages of the parasite. Cysts were not recorded from a small sample of perch fry (aged 4–6 weeks). There was a peak of prevalence, and intensity of the infection in juvenile perch (aged 8–9 months), while the prevalence and intensity in adult perch (aged 1–1 and over) was low. In adult perch there was a seasonal November‐F

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00136.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.Sheepshead minnows,Cyprinodon variegatusLacépède, exposed to 5.5 to 31 μg/1 of the herbicide trifluralin, throughout their first 28 days of life, developed a heretofore undescribed vertebral dysplasia. This dysplasia consisted of semi‐symmetrical hypertrophy of vertebrae (three to 20 times normal), characterized by foci of osteoblast and fibroblasts actively laying down bone and bone precursors. Effects of the abnormal vertebral development were dorsal vertebral growth into the neural canal, ventral compression of renal ducts, and longitudinal fusion of vertebrae. Pish, exposed for 51 days to 16.6 μg/1 trifluralin and thereafter depurated for 41 days, showed no increase in vertebral dysplasia during depuration; however, residual spinal column damage was evident. Serum calcium concentrations were elevated in adult fish exposed for 4 days to 16.6 μg/1 trifluralin. Fluorosis or mimicry of hypervitaminosis A are considered possible mechanisms for the osseous effect, but are not considered to be the only possible causes. The highly predictable nature of this disorder in experimental exposures strengthens the probability that young fish may serve as experimental models for determining effects of chemicals on early vertebrate ontogeny, particularly in regard to skeletal devel

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00137.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.Rainbow trout were fed diets contaminated with either PCB (Aroclor 1254, 500 μg/g dry food) or Mirex (500μg/gdry food). There was no apparent effect of PCB on thyroid histology or on serum thyroid hormone levels. Mire effected significant reductions in serum T4(P<0.05) and T3levels (P<0.01) without apparent change om the histological appearance of the thyroi. Liver weights and total liver lipid content were significantly (P<0.001) greater in PCB fed fish compared with controls as was the carcass lipid content (P<0.01). Mirex had no apparent effect on liver size or liver lipid content but there was a decline in carcass lipid content (P<0.02) which persisted 25 days after returning Mirex‐fed fish to the control diet (P<0.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00138.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.Mass mortalities in silver carp were related to infection of handling lesions withProteus rettgeri, a gram negative bacterium normally found in the gut of poultry. Poultry faeces are used extensively to fertilize carp ponds and experimental infections showed that the condition could be reproduced by scarification and exposure to the micro‐organism or by its inoculatio

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00139.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.Examination of the digestive tract of rainbow trout fry infected withHexamita salmonisrevealed no pathological changes in the epithelial cells of the pyloric caeca or upper intestine even where the parasites were closely apposed to the brush border of these cells. No invasion of the epithelium by the parasites was observed, although examples of shrinkage necrosis (apoptotic bodies) of epithelial cells were often found. The ultrastructure of the parasite resembled that of the closely relatedGiardia lamblia. Despite the lack of pathological changes to the intestinal epithelium, treatment of the fish to remove the parasites greatly reduced mortalities.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00140.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00141.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00142.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00143.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY