First isolation, identification and characterisation of Tenacibaculum maritimum in Norway, isolated from diseased farmed sea lice cleaner fish Cyclopterus lumpus L

• Published in: Aquaculture
• Main Authors: Småge, Sverre Bang, Frisch, Kathleen, Brevik, Øyvind Jakobsen, Watanabe, Kuninori, Nylund, Are
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2016
• Subjects: Atlantic salmon; Fish pathogen; Lumpfish; Salmon lice; VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Marinbiologi: 497; Norway; Salmo salar
• Online Access: https://hdl.handle.net/1956/12223; https://doi.org/10.1016/j.aquaculture.2016.06.030

The use of cleaner fish as biological controls of salmon lice (Lepeophtheirus salmonis) has increased exponentially in the last decade in Norwegian Atlantic salmon (Salmo salar) production. This alternative to chemical treatments has resulted in the emergence of lumpsucker (Cyclopterus lumpus) hatcheries and culture facilities in Norway. It has been shown that the use of lumpsuckers can be an effective, biological approach for the removal of salmon lice, but it has also been shown that there are a number of biological challenges (i.e. parasites and bacteria) with the production and use of these fish. This study describes the first case of isolation of Tenacibaculum maritimum, a significant fish pathogen worldwide, in cultured juvenile lumpsuckers in Norway. The fish were lethargic and showed skin lesions characterised by increased mucus production and presence of whitish necrotic tissue especially in the head region. Skin scrapings revealed large amounts of bacteria dominated by rod-shaped Tenacibaculum-like bacteria, which were shown to be closely related to T. maritimum type strain through genetic and phenotypic characterisation. Histopathological analysis showed that the bacteria was closely associated with the pathology and therefore could be contributing to the disease and/or mortality. publishedVersion