Abstract

The Atlantic lumpfish (Cyclopterus lumpus) is a small marine fish found throughout the eastern Atlantic Ocean, North Sea, Baltic Sea, and Barents Sea. The species shows promise as a biological delousing agent for maintaining low levels of sea lice in Atlantic salmon sea cages, similar to several species of wrasse that have been used since the 1990s. They are collectively termed "cleaner fish" and feed on a wide range of marine invertebrates, including sea lice. The majority of wrasse is sourced from wild fishery, while almost all lumpfish are produced in land-based farming facilities. The demand for cleaner fish in Norwegian aquaculture is high, and almost 25 million individuals were put to sea in the year 2014.

Infectious diseases have become a significant challenge for cleaner fish management, especially different bacterial pathogens such as atypical Aeromonas salmonicida, Vibrio salmonicida, Vibrio ordalii, Pseudomonas anguilliseptica and Pasteurella sp. Recently, two national surveys reported lumpfish mortality levels from just below 25% to above 50%, where bacterial infections were an important cause.

Fish vaccination is an important contributor to reducing the mortality and infection pressure caused by disease. Current research is investigating the lumpfish immune system in order to develop effective vaccines, especially towards the diseases atypical furunculosis, vibriosis and pasteurellosis. The fish seem to have a high activity of non-specific defense mechanisms, such as phagocytosis and respiratory burst, and appear capable of producing specific antibodies against potential antigens. For that reason, the implementation of vaccination and immunostimulation in lumpfish management could be important for reducing the incidence of disease and improving the welfare of this species.

* Presenting author