The abundance of an invasive freshwater snail Tarebia granifera (Lamarck, 1822) in the Nseleni River, South Africa

[1 ] Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa

[2 ] Ezemvelo KZN Wildlife, Richards Bay, South Africa

[3 ] Department of Botany, Grahamstown, South Africa

[4 ] Department of Biology and Mathematics & Statistics, Acadia University, Wolfville, Nova Scotia, Canada

[5 ] Centre for Invasion Biology, South African Institute for Aquatic Biodiversity, South Africa