Zoothamnium duplicatum Kahl, 1933

Report as epibiont on bryozoans: This species was reported as epibiont on marine bryozoans Cribrilina punctata (Hassal, 1841), Alcyonidium polyoum (Hassal, 1841) and Crisia eburnean (Linnaeus, 1758) in Kiel Bay, the North Sea (Precht 1935).

Report as epibiont on other host: The species was found on Cordylophora caspia (Pallas, 1771) and Campanulina lacerata (Johnston, 1847) from Kiel Bay, the North Sea (Precht 1935). Shinn et al. (2015) found the species at the American horseshoe crab Limulus polyphemus Linnaeus, 1758, originating from Delaware Bay, USA. It was also found on mysid Mesopodopsis tenuipes Hanamura, Koizumi, Sawamoto, Siow & Chee, 2008 in the Merbok mangrove brackish water in north-western Peninsular Malaysia (Hamamura et al. 2010).