1 Sections of Parasitology and Aquatic Diseases & Food Safety and Zoonoses, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej 100, 1870, Frederiksberg C, Denmark. hmad@sund.ku.dk.
2 Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, 16802, USA.
3 South African Institute for Aquatic Biodiversity, Makhanda, RSA.