PATHOBIOLOGICAL AND ULTRASTRUCTURAL STUDIES OF INFESTED SPOTTED SEABASS, DICENTRARCHUS PUNCTATUS IN DAMIETTA REGION, EGYPT

Document Type : Original Article

Authors

1 Department of Zoology, Faculty of Science, Damietta University, Egypt

2 Department of Environment, Faculty of Science, Damietta University, Egypt

Abstract

The spotted seabass, Dicentrarchus punctatus (Bloch, 1792) is ecologically and economically important marine fish species in Damietta region. However, their infection with crustacean para-sites is an important topic in the identification of these parasites and this histopathological study investigates the aspect of parasitism and diseases that may affect their well-being. Herein, we il-lustrate copepode parasite, Lernanthropus Kroyeri and isopod (Nerocila spp.) infecting the gill filaments of a commercial marine spotted sea bass, D. punctatus and detail histopathological changes to infected tissues under light and scanning electron microscopes. A total of 75 D. punc-tatus fishes were collected from Boghaz Damietta area seasonally 2022. Using a light micro-scope, L. kroyeri was mostly discovered clinging to gill filaments ventral side, close to inter-branchial septum. The parasite attached itself by grabbing hold of the gill filaments with its an-tennae. Lamellary edoema, fusion of the secondary lamellae as a result of considerable epithelial growth, erosive changes to the branchial lamellar epithelium, and necrosis in the terminals of the primary lamellae where the parasites penetrated were also present. According to Isopoda (Nerocila spp.), the epidermal cells of the D.punctatus with isopoda infestation displayed vacuo-lar and ballooning degeneration with isolated superficial sloughing to deep ulcerations. Signifi-cant hyaline degeneration and Zenker's necrosis were present in the underlying muscles, along with an infiltration of localized mononuclear cells and melanophage cells. These results ex-plained specific infection patterns of the identified parasites in relation to their hosts under LM and SEM microscopes.

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