Hella Schwegler Hella Schwegler Jeff Schreiner Jeff Schreiner Maria Prüllage Maria Prüllage Karoline Lipnik Karoline Lipnik Astrid S. Holzer Astrid S. Holzer Eva Lewisch Eva Lewisch Wiley 2026 This case report presents a recent case of scuticociliatosis in a whitetip reef shark (Triaenodon obesus), housed at a zoo (Haus des Meeres Aqua Terra Zoo, Vienna, Austria). Clinical signs such as uncoordinated swimming and body tilt were observed prior to death. Postmortem examination and magnetic resonance imaging (MRI) revealed significant brain lesions consistent with granulomatous or necrotising encephalitis. Histopathology and molecular diagnostics confirmed the presence of the scuticociliate Miamiensis avidus and/or Philasterides dicentrarchi in the brain, with extensive tissue invasion. This case underscores the pathogenicity of scuticociliates in elasmobranchs, highlighting the need for effective management practices in aquaria to prevent or mitigate such infections. In this study, we present the first documented infection with scuticociliates in the whitetip reef shark. PDFDocument eng 2026-07-17T08:23:02.239626541Z 2026 Magnetic Resonance Imaging MRI Scuticociliatosis Shark Disease Triaenodon Obesus 1410413 b application/pdf http://creativecommons.org/licenses/by-nc-nd/4.0/