1. Department of Ichthyology and Fisheries Science, P.O. Box 94, Rhodes University, Grahamstown, 6140, South Africa.
2. South African Institute for Aquatic Biodiversity, Private Bag X1015, Grahamstown, 6140, South Africa.
3. Faculdade Ciências da Universidade Agostinho Neto (FCUAN), Luanda, Angola.