Ulcerative dermatitis in wild dusky grouper Epinephelus marginatus (Lowe) from Libyan waters



Rizgalla J, Bron J, Shinn A, Herath T, Paladini G & Ferguson H (2016) Ulcerative dermatitis in wild dusky grouper Epinephelus marginatus (Lowe) from Libyan waters. Journal of Fish Diseases, 39 (12), pp. 1457-1466.

In the period 2013–2015, wild dusky grouper,Epinephelus marginatus(Lowe), caught in Libyan coastal waters and ranging in size from 42 to 92cm in total length, were observed to have distinctive skin lesions of unknown aetiology. Histopathologically, the lesions comprised a multifocal, unilateral or bilateral dermatitis, involving the epidermis, superficial dermis and scale pockets, and sometimes, in severe cases, the hypodermis. Severe lesions had marked epidermal spongiosis progressing to ulceration. Healing was observed in some fish. Bacteria and fungi could be isolated from severe lesions, although they were not seen histopathologically in early-stage lesions. By contrast, metazoan parasite eggs were observed in the dermis and epidermis of some fish with mild and moderate dermatitis. Unidentified gravid digeneantrematode parasites carrying similar eggs were also seen within the blood vessels of the deep and superficial dermis. The cause of this distinctive condition, termed dusky grouper dermatitis (DGD), and its potential impact upon already threatened Mediterranean wild dusky grouper populations and upon cultured grouper more widely have yet to be established.

dusky grouper dermatitis DGD; haemorrhage; parasite eggs; pathology; scale pockets; skin lesions

Journal of Fish Diseases: Volume 39, Issue 12

Publication date31/12/2016
Publication date online04/05/2016
Date accepted by journal25/02/2016

People (2)


Professor James Bron
Professor James Bron

Professor, Institute of Aquaculture

Professor Hugh Ferguson
Professor Hugh Ferguson

Emeritus Professor, Institute of Aquaculture