title: Ulcerative dermatitis in wild dusky grouper Epinephelus marginatus (Lowe) from Libyan waters.
abstract: In the period 2013-2015, wild dusky grouper, Epinephelus marginatus (Lowe), caught in Libyan coastal waters and ranging in size from 42 to 92 cm 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 digenean trematode 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.
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK. jamilarizgalla@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Rizgalla
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Bron
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.|Fish Vet Group Asia Limited, Bangkok, Thailand.
authors.forename: A P
authors.initials: AP
authors.lastname: Shinn
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.
authors.forename: T K
authors.initials: TK
authors.lastname: Herath
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.
authors.forename: G
authors.initials: G
authors.lastname: Paladini
authors.affiliation: Marine Medicine Programme, School of Veterinary Medicine, St. George's University, Grenada, West Indies.
authors.forename: H W
authors.initials: HW
authors.lastname: Ferguson
mesh_terms: D000818:Animals; D001492:Bass; D003872:Dermatitis / Q000453:epidemiology / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D056727:Endangered Species; D005393:Fish Diseases / Q000453:epidemiology / Q000382:microbiology / Q000469:parasitology / Q000473:pathology*; D008002:Libya / Q000453:epidemiology
keywords: dusky grouper dermatitis DGD; haemorrhage; parasite eggs; pathology; scale pockets; skin lesions