1. Unit for Environmental Sciences and Management; North-West University; Potchefstroom 2520 South Africa
2. South African Institute for Aquatic Biodiversity; Private Bag 1015 Grahamstown 6140 South Africa
3. Laboratory for Electron Microscopy; Chemical Resource Beneficiation; North-West University; Potchefstroom 2520 South Africa
4. Laboratory of Aquatic Ecology, Evolution and Conservation; University of Leuven; Leuven 3000 Belgium