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Aspects of the ecology, life cycle and pathology of Lamproglena clariae (Copepoda:Lernaeidae), collected from the gills of Clarias gariepinus from the Vaal River system, South AfricaTsotetsi, Ana Mbokeleng 16 October 2008 (has links)
Ph.D. / Female adult specimens of Lamproglena clariae attach to gill filaments of freshwater fish of the family Clariidae, penetrate the gill tissue and consume blood. Previously, studies have been done on the taxonomy of this parasite, but little research has been published on biological aspects. Hence, it was the aim of this study to determine and record L. clariae’s aspects of biology such as ecology, life cycle and pathology. The study was conducted through both field and laboratory observations with specimens collected from the Vaal Dam and Vaal River Barrage. A positive correlation was observed between the host's physical dimensions and the size of the parasite, parasites from both sites preferred the fourth gill and the median part of the gill arch for attachment. There was no significant host gender preference by parasites. Three free living nauplius stages, four copepodite, a cyclopoid and adult stages were recorded as life stages of this parasite. Observations suggested that development of larval stages of L. clariae is influenced by both photoperiod and temperatures. Furthermore low infestation success of the experimental fish was observed. This parasite caused localised infestation as varying degrees of swelling of gill filaments were observed only in the vicinity of its attachment site. Histological examination revealed epithelial hyperplasia, resulting in fusion of gill lamellae and necrosis of the host tissue in the vicinity of the parasite. No correlation exists between the infestation intensity and fish haematocrit values. Although L. clariae causes localized infestation, high intensity of infestation may be detrimental to the fish. Hyperplasia of epithelial tissue resulting in fusion of lamellae would result in restriction of oxygen passage and thus hinder the process of respiration of the host. / Prof. A. Avenant-Oldewage
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