The use of cestode parasites from the largemouth yellowfish, Labeobarbus kimberleyensis (Gilchrist and Thompson, 1913) in the Vaal Dam, South Africa as indicators of heavy metal bioaccumulation

Twenty Largemouth yellowfish Labeobarbus kimberleyensis (Gilchrist and Thompson, 1913) were collected in the Vaal Dam in the vicinity of RAU Island (Groot Eiland). Muscle-, spinal cord- and liver tissue were removed from each fish and the intestine opened to obtain Bothriocephalus acheilognathi. The tissues were then digested in a microwave digester and the metal concentrations were determined in each tissue with an ICP-MS. The results indicate that the worms have potential use as bioindicators, because in 8 elements (lithium, beryllium, manganese, selenium, mercury, thallium, lead and uranium) out of the 23 elements measured the cestodes have accumulated the highest metal concentrations, and in 7 elements (chromium, iron, zinc, molybdenum, cadmium, tin and barium) out of 23 elements the cestodes had the second highest metal accumulation recorded.