Monitoring the Cause of Mortality in Some Marine Fishes in Matrouh Governorate, Egypt During the Summer 2008

摘要

This study was designed to declare the cause of sudden mortality in different types of marine fishes, namely red grouper, sea bass, sea bream and rabbit, along the sea shore of Matrouh-Saloum in Matrouh Governorate, Egypt during the period from July to October, 2008. The recorded clinical signs in the collected fishes were external hemorrhage, inflamed hemorrhagic vent and abdominal distension in some fishes, while others were apparently normal. P/M examination revealed mottled liver, congestion of the internal organs and also severe inflammation of both gastric and intestinal mucosa with excess amount of mucoid exudates. Histopathological examination revealed variable degrees of hepatocytic vacuolar degeneration, circumscribed areas of melanomacrophage cells aggregations in between the hepatocytes, vasculitis and bile duct hyperplasia. Spleen showed focal depletion in the haemopoietic tissue, increased number of melanomacrophage centers and congestion in the spleenic blood vessels. Brain showed vascular congestion and oedema in the cerebral cortex together with focal gliosis. Bacteriological examination proved the isolation of Photo. bacterium sp. (Pasteurella damsela) in association with the above mentioned clinical and histopathological changes as a primary cause. P. damsela identification was done through phenotypic, culture and biochemical characters. In conclusion: Pasteurella damsela could be incriminated as the cause of sudden acute mortality of marine water fishes in Matrouh governorate, Egypt during this period