Effect of Abrupt Environmental Deterioration on the Eruption of Vibriosis in Mari-Cultured Shrimp, Penaeus indicus , in Egypt

摘要

Massive scale mortalities attacked, Penaeus indicus , cultured within two earthen pond shrimp farms at Muthallath El-Deeba Damietta on the North East coast of the Mediterranean Egypt, during the period extended from September to November 2014. Losses were rigorous in the farm use water directly from Lake Manzala approaching 100% compared to other draws water from El-Medan canal 40%. Mortalities started concomitantly with the onset of unstable climate in the Mediterranean sea. Epidemics hit premature shrimp after 4.5 month of culture. Affected shrimp showed signs of septicemia. Majority of investigated shrimp samples 77.7% were found to be infected. Vibrio harveyi 34.88, Vibrio alginolyticus 25.58, Vibrio vulnificus 22.09 and Vibrio mimicus 17.44% were solely retrieved from moribund shrimp specimens. Similar vibrios were also detected in water and sediments samples collected from source water and the studied farms. Results support considerable evidence links between deterioration of environmental water quality measures and the eruption of vibrio epidemics in the studied farms. Unfavorable values were recorded for un-ionized ammonia, nitrite, dissolved oxygen and some noxious heavy metals. Variable degenerative and proliferative changes were detected in histopathological studies.