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العنوان
Major Challenges Facing European Seabass Seeds in Egyptian Marine Hatcheries /
المؤلف
Ragab, Reham Hassan Ibrahim.
هيئة الاعداد
باحث / ريهام حسن ابراهيم رجب
مشرف / علاء الدين عبد المعطى محمد عيسي
مشرف / رياض حسن خليل
مشرف / محمد ابراهيم عبد السلام
الموضوع
vibriosis. amyloodiniosis.
تاريخ النشر
2022.
عدد الصفحات
74 p. :
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
البيطري
تاريخ الإجازة
1/1/2022
مكان الإجازة
جامعة القاهرة - كلية الطب البيطري - Medicine
الفهرس
Only 14 pages are availabe for public view

from 98

from 98

Abstract

Amyloodiniosis and vibriosis are serious diseases in European seabass (Dicentrarchus labrax) hatcheries with noticeable high mortality. This study was conducted on tank-cultured D.labrax frys at a private marine hatchery near Mariout Lake (Alexandria, Egypt). Frys showed a high mortality rate (70%), lethargy, darkening, asphyxia, ascites, and velvety skin appearance. Both infectious agents were presumptively identified in all investigated frys. The identities of the two recovered agents were confirmed by molecular assay and phylogenetic analysis. On the tissue level, histopathological examination of skin, splenic, and renal tissue indicated severe altera¬tions due to the direct impacts of both infections. On the cellular level, scanning electron micrographs showed both protozoal and bacterial pathogens on/in gill epithelial cells in solitary and colonial forms. Vibrio alginolyticus showed variable results for tested antibiotics, with a higher sensitivity to florfenicol. A successful control strategy was strictly adopted to overcome infections and stop mortalities. Copper sulphate and hydrogen peroxide were efficiently applied to tank water to overcome A. ocellatum infections. Further, florfenicol was effectively used to overcome systemic V. alginolyticus infections. The efficacy of treatments was confirmed by the absence of infectious agents in randomly collected fish samples. To the best of the authors’ knowledge, this study is one of the earliest Egyptian studies that dealt with the dilemma of mass kills associated with external parasitic/systemic bacterial infections among hatchery-reared European seabass.