On cestode and digenean parasites of &lt;i&gt;Clarias gariepinus&lt;/i&gt; (Burchell, 1822) from the Rietvlei Dam, South Africa

M Barson,A Avenant-Oldewage

doi:10.4102/ojvr.v73i2.154

Abstract

Sharptooth catfish, Clarias gariepinus, from the Rietvlei Dam near Pretoria, South Africa were examined for internal platyhelminth parasites. Two adult cestodes, Polyonchobothrium clarias (stomach) (prevalence 71%, mean intensity = 5, n = 7) and Proteocephalus glanduliger (anterior intestine) (prevalence 14%, mean intensity = 2, n = 7), were found in the gut while metacercariae of one larval digenean, Ornithodiplostomum sp. (prevalence 14%, mean intensity = 140, n = 7), were found encysted in the muscles. The morphology of these species, based on light and scanning electron microscopy as well as histological analysis, and how they differ from previously described specimens, are discussed. Ornithodiplostomum is a new record in southern Africa. Infection levels of the host fish were mild compared to records from previous surveys.

Highlights

Fish helminthology in southern Africa is not as widely studied as other aspects of aquatic parasitology and fish biology
In 1984, Van As and Basson compiled a checklist of South African freshwater fish parasites, but many new species have been discovered since (Khalil & Polling 1997)
The objectives of this paper were to identify and classify the internal platyhelminth parasites collected from the host fish (Clarias gariepinus) based on their morphological features, and to note their prevalence and mean intensity in the Rietvlei Dam

Summary

Introduction

Fish helminthology in southern Africa is not as widely studied as other aspects of aquatic parasitology and fish biology. This is probably because helminths mainly infect the internal organs, predominantly the gastrointestinal tract which, for humans, does not comprise the edible portion of the fish. In 1984, Van As and Basson compiled a checklist of South African freshwater fish parasites, but many new species have been discovered since (Khalil & Polling 1997). In 1984, Van As and Basson compiled a checklist of South African freshwater fish parasites, but many new species have been discovered since (Khalil & Polling 1997). Paperna (1996) published a concise update of the parasitic diseases of fish in Africa, in which the occurrence and geographical distribution, life cycles, pathology, epizootiology and control of the parasites is described

Objectives

Methods

Results