Dropsy of mixed aetiology in Catla catla (Ham.)
Like other intensive aquaculture systems, composite fish culture also aims at increasing fish production by various intensification approaches such as increased stocking rates, increased feeding and fertilization programme. Under such conditions it is inevitable that imminical conditions enhancing the development of disease will be encountered (Kumar et al., 19 ) Several workers have already reported occurrance of diseases in composite fish culture ponds (Pal and Tripathi, 1978; Dey et al., 1982 ). During routine examination of fish samples from composite fish culture ponds under fish health monitoring programme, authors came across few cases of dropsy in Catla catla at several occasions. Thorough investigations into dropsy disease in fish dates back to 1930 by Schaperclaus. Infectious Dropsy and Hydrops have also been described in European carp farms (Tomasec, 1941; Otta, 1963 and Ghittino, 1968). Gopalakrishnan (1961) has reported infectious dropsy of Indian major carps and its experi mental induction. Most authors considered infectious Dropsy of carp (IDC) to be contagious, but expressed doubt about its aetiology. Some workers considered it to be a bacterial, some a viral and others a disease caused by a combination of both virus and bacterium. Only recently Fijan and his associates have isolated and named a virus Rhabdoyirus carpio as the most likely cause of acute infectious dropsy of carps (Fijan, 1972). However, the etiological agent of the infections dropsy in cultured major carps in India has been reported to be species of Aeromonas (Gopalakrishnan, 1961). Pal and Tripathi (1968), though did not isolate the casual agent, could treat the disease fully using terramycin in the feed. However, the present cases are interesting from the view of its mixed aetiology from which strain of bacterium Aeromonas hydrophila ssp. hydrophila and spores of myxosporidian parasite have been isolated. The present observation aims towards understanding the disease process.
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Format: | Project biblioteca |
Language: | English |
Published: |
1986
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Online Access: | https://fao-prod.atmire.com/handle/20.500.14283/AC222E http://www.fao.org/3/a-ac222e.htm |
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