Journal article

Repeated sublethal freshwater exposures reduce the amoebic gill disease parasite, Neoparamoeba perurans, on Atlantic salmon

Daniel William Wright, Barbara Nowak, Frode Oppedal, Phil Crosbie, Lars Helge Stien, Tim Dempster

Journal of Fish Diseases | WILEY | Published : 2018


Freshwater bathing is one of the main treatment options available against amoebic gill disease (AGD) affecting multiple fish hosts in mariculture systems. Prevailing freshwater treatments are designed to be long enough to kill Neoparamoeba perurans, the ectoparasite causing AGD, which may select for freshwater tolerance. Here, we tested whether using shorter, sublethal freshwater treatment durations are a viable alternative to lethal ones for N. perurans (2-4 hr). Under in vitro conditions, gill-isolated N. perurans attached to plastic substrate in sea water lifted off after ≥2 min in freshwater, but survival was not impacted until 60 min. In an in vivo experiment, AGD-affected Atlantic salm..

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University of Melbourne Researchers


Awarded by University of Tasmania Animal Ethics Committee

Funding Acknowledgements

We thank Tina Oldham for qPCR analyses, and many other staff and students at the Institute of Marine and Antarctic Studies, University of Tasmania for technical support during the AGD infection experiment. Thanks also to Tom Fraser who assisted with statistical analyses. Funding came from an Australian Research Council Future Fellowship awarded to TD. Animal ethics approval for the AGD infection experiment was provided by the University of Tasmania Animal Ethics Committee (ID: A15344).