Application of a fish health assessment index and associated parasite index to Clarias gariepinus (Teleostei: Clariidae) in the Vaal River system, South Africa

  • D Crafford
  • A Avenant-Oldewage

Abstract

The aim of this study was to determine if the fish health assessment index (HAI) developed in the USA and associated parasite index (PI), when applied to Clarias gariepinus at two localities in the upper and middle Vaal River system, could distinguish between localities on the grounds of water quality. Elevated HAI values, correlating with poorer chemical and physical water quality, were recorded from the Vaal River Barrage site. Parasite data were congruent with the main PI premise that prevalence and intensity of endoparasite infection would be higher at the more polluted locality, with the converse being recorded for ectoparasites. It was therefore possible to distinguish between localities with different water quality, based on parasites present on the hosts.

Keywords: aquatic health; biological monitoring; environmental management; indicator species; Vaal Dam; Vaal River Barrage

African Journal of Aquatic Science 2009, 34(3): 261–272

Author Biographies

D Crafford
Department of Zoology, University of Johannesburg, PO Box 524, Auckland Park, Johannesburg 2006, South Africa; current address: Clinvet International Pty Ltd, PO Box 11186, Universitas 9321, South Africa
A Avenant-Oldewage
Department of Zoology, University of Johannesburg, PO Box 524, Auckland Park, Johannesburg 2006, South Africa
Section
Articles

Journal Identifiers


eISSN: 1727-9364
print ISSN: 1608-5914