Faculty of Veterinary Science
Department of Paraclinical Sciences (Veterinary)
Selected Highlights from Research Findings
Most South African rivers and dams are severely degraded and polluted. Aquatic animals, for example, the Nile crocodile (Crocodylus niloticus) and fish, are sensitive and very helpful indicators of freshwater ecosystem health. Nile crocodiles are becoming more threatened due to habitat destruction and the deterioration of freshwater quality. The investigation into the Nile crocodile mortalities, ascribed to pansteatitis, is still ongoing.
During a feeding experiment at the Faculty of Veterinary Science, it was determined that affected fat, from crocodiles that had died of pansteatitis, did not cause the disease in healthy crocodiles that consumed the fat over a period of a month. The hypothesis that cannibalism (eating sick crocodiles) caused the disease in healthy crocodiles after they had consumed the affected crocodiles could not be confirmed.
Pansteatitis was also discovered in sharptooth catfish (Clarias gariepinus) and large-scale yellowfish (Barbus marequensis) from the upper Olifants River. Inflammation of the fat deposits of fish has not been reported before from the upper Olifants River. However, similar lesions were recently found by Dr David Huchzermeyer (a PhD candidate from the Department of Paraclinical Sciences) in sick catfish from the Olifants River Gorge during the Nile crocodile die-off (pansteatitis) in 2009. It seems as if aluminium and iron are playing important contributing roles. Special stains were imported by the department to stain aluminium and iron in tissue samples from crocodiles and fish. Preliminary results look very promising.
Contact person: Dr JG Myburgh.
|
