Pathological investigation of gill, intestine, liver and kidney of naturally infected Streptococcosis in ornamental fish, tiger oscar, Astronotus ocellatus Velappan Muralidharan1,*, Munusamy Deecaraman2 1Research Scholar, Department of Biotechnology, AMET University, Kanathur, Chennai-603112, India 2Dean/Emeritus Professor, Department of Industrial Biotechnology, Dr. M.G.R Educational and Research Institute, Maduravoyal, Chennai-600095, India *Corresponding Author E-mail: muralidharanmicro@gmail.com
Online published on 24 August, 2018. Abstract The objective of this study was to investigate the occurrence of Streptococcus iniae infection and its histopathological lesion in gills, intestine, liver and kidney of naturally infected adult Tiger oscar fish (Astronotus ocellatus) obtained from the leading pet aquarium farm in Chennai city. The most consistent gross findings were marked, dermal haemorrhages, inflammation and congestion of the internal organs, particularly the gill, intestine, liver and kidneys. Other observations were enteritis and color fading of pectoral and ventral fins. Histopathological investigation revealed hyperplasia and necrosis of gill tissue, elongation of columnar cells, ulceration of intestinal villi and vacuolization. Hyaline droplet degeneration in the liver and cellular infiltration in the kidneys were seen. Further, there was large number of Cocci seen in the blood capillaries. In some liver tissues granulomatous oedema was also observed. Naturally infected S.iniae caused severe septicaemia and dermal haemorrhages. In control fishes these pathological changes were not observed. This is the first histopathological report on Tiger oscar fish naturally infected with S.iniae. Top Keywords Haemorrhages, post-mortem, histopathology, necrosis, abnormalities. Top |