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Eighty largemouth yellowfish, Labeobarhus kimherleyensis, were collected between April 2005 and February 2006 with gill nets close to the island (26° 52, 249‱ S, 28° 10, 249‱ E) in the Vaal Dam. The fish were killed, weighed and their length determined. Muscle, liver and spinal cord tissues were collected from each fish and the intestines removed and opened to expose Bothriocephalus acheilognathi. The tapeworms were collected in glass bottles and frozen. Water and sediment, as well as liver, muscle and tapeworm samples were digested and thereafter metal concentrations of 23 elements (lithium, beryllium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium, tin, antimony, tellurium, barium, mercury, thallium, lead and uranium) were determined with an ICP-MS. Bioconcentration of metals (selenium, mercury, and lead during autumn; copper, zinc, selenium, cadmium, antimony, thallium and mercury during winter; lithium, zinc, selenium, cadmium and antimony during spring; and zinc during summer) occurred in tapeworms. The highest mean value was recorded in sediment, followed by water, tapeworms and host tissue. A seasonal trend showed that a higher concentration of the metals had accumulated in tapeworms during winter when water levels were at their lowest. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]