A parasite outbreak in notothenioid fish in an Antarctic fjord
Thomas Desvignes,
Henrik Lauridsen,
Alejandro Valdivieso,
Rafaela S. Fontenele,
Simona Kraberger,
Katrina N. Murray,
Nathalie R. Le François,
H. William Detrich, III,
Michael L. Kent,
Arvind Varsani,
John H. Postlethwait
Affiliations
Thomas Desvignes
Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA; Corresponding author
Henrik Lauridsen
Department of Clinical Medicine, Aarhus University; Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
Alejandro Valdivieso
Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), Barcelona Spain
Rafaela S. Fontenele
The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine and School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
Simona Kraberger
The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine and School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
Katrina N. Murray
Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
Nathalie R. Le François
Laboratoire Physiologie, Aquaculture et Conservation, Biodôme de Montréal/Espace pour la vie, 4777 Avenue Pierre-De Coubertin, Montreal, QC H1V 1B3, Canada
H. William Detrich, III
Department of Marine and Environmental Sciences, Northeastern University Marine Science Center, 430 Nahant Rd, Nahant, MA 01908, USA
Michael L. Kent
Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA
Arvind Varsani
The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine and School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA; Structural Biology Research Unit, Department of Integrative Biomedical Sciences, University of Cape Town, 7925 Cape Town, South Africa; Corresponding author
John H. Postlethwait
Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA; Corresponding author
Summary: Climate changes can promote disease outbreaks, but their nature and potential impacts in remote areas have received little attention. In a hot spot of biodiversity on the West Antarctic Peninsula, which faces among the fastest changing climates on Earth, we captured specimens of two notothenioid fish species affected by large skin tumors at an incidence never before observed in the Southern Ocean. Molecular and histopathological analyses revealed that X-cell parasitic alveolates, members of a genus we call Notoxcellia, are the etiological agent of these tumors. Parasite-specific molecular probes showed that xenomas remained within the skin but largely outgrew host cells in the dermis. We further observed that tumors induced neovascularization in underlying tissue and detrimentally affected host growth and condition. Although many knowledge gaps persist about X-cell disease, including its mode of transmission and life cycle, these findings reveal potentially active biotic threats to vulnerable Antarctic ecosystems.
