A parasite outbreak in notothenioid fish in an Antarctic fjord

• Published in: iScience
• Main Authors: 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
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2022
• Subjects: Biological sciences; Zoology; Microbiology; Parasitology; Microbiology parasite; Science; Q; Antarctic; Antarctic Peninsula; Southern Ocean; Antarc*
• Online Access: https://doi.org/10.1016/j.isci.2022.104588; https://doaj.org/article/f202e0783b344c31b88a58f497c11417

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.