Temperature-driven proliferation of Tetracapsuloides bryosalmonae in bryozoan hosts portends salmonid declines.
Proliferative kidney disease (PKD) is an emerging disease of salmonid fishes. It is provoked by temperature and caused by infective spores of the myxozoan parasite Tetracapsuloides bryosalmonae, which develops in freshwater bryozoans. We investigated the link between PKD and temperature by determining whether temperature influences the proliferation of T. bryosalmonae in the bryozoan host Fredericella sultana. Herein we show that increased temperatures drive the proliferation of T. bryosalmonae in bryozoans by provoking, accelerating and prolonging the production of infective spores from cryptic stages. Based on these results we predict that PKD outbreaks will increase further in magnitude and severity in wild and farmed salmonids as a result of climate-driven enhanced proliferation in invertebrate hosts, and urge for early implementation of management strategies to reduce future salmonid declines.
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School of Biological Sciences, Philip Lyle Research Building, University of Reading, Whiteknights, PO Box 228, Reading RG6 6BX, UK.
Lockwood
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Okamura
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D000818:Animals; D002013:Bryozoa / Q000469:parasitology*; D021821:Communicable Diseases, Emerging / Q000469:parasitology / Q000662:veterinary; D056890:Eukaryota / Q000254:growth & development* / Q000502:physiology; D005393:Fish Diseases / Q000469:parasitology*; D016133:Polymerase Chain Reaction; D012487:Salmonidae / Q000469:parasitology*; D012621:Seasons; D013696:Temperature; D013997:Time Factors