|Title||Aetiology and histopathology of a systemic phaeohyphomycosis in farmed lumpfish, Cyclopterus lumpus|
|Publication Type||Journal Article|
|Year of Publication||2018|
|Authors||Johnson, KE, Freeman, MA, Laxdal, B, Kristmundsson, A|
|Journal||Bulletin- European Association of Fish Pathologists|
Lumpfish being reared as biological control agents for sea lice removal from farmed Atlantic salmon developed mycotic lesions in their skeletal muscle, heart, and kidneys. After necropsy and histopathology, the fish were diagnosed with phaeohyphomycosis, thought to be caused by Exophiala sp. Samples of lesions were sent for molecular analysis to confirm the diagnosis. PCR and DNA sequencing confirmed the presence of two fungal species of black yeasts (Chaetothyriales) Exophiala psychrophilia and Cyphellophora sp. Exophiala spp. are known pathogens of farmed salmon, wild fishes, and other animals including humans. Cyphellophora spp. are normally found colonising plants and land animals, but have not been reported from fish. Most phaeohyphomycoses in captive fish are thought to be secondary to a compromised immune system arising from infections with primary pathogens, and/or husbandry problems. The identification of these fungal infections in cultured lumpfish and the increasing reports of microsporidiosis in captive lumpfish, are a reminder that further research is needed to understand the physiology and husbandry needs of this relatively new fish to aquaculture, especially with respect to opportunistic pathogens. In addition, the zoonotic potential of these pathogens in the aquaculture environment should be evaluated.