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dc.contributor.advisorVan As, J. G.
dc.contributor.advisorBasson, Linda
dc.contributor.authorChristison, Kevin William
dc.date.accessioned2017-06-19T06:51:06Z
dc.date.available2017-06-19T06:51:06Z
dc.date.issued2002-06
dc.identifier.urihttp://hdl.handle.net/11660/6376
dc.description.abstractEnglish: The Okavango Delta has received much popularity for the host of wildlife that it sustains. More recently it has gained increasing interest for the rich diversity of fish species that occur there. The fishes of the Okavango are also becoming increasingly important as a natural resource attracting revenue to Botswana in the forms of ecotourism and aquaculture and also as an important food source for the local community. The Okavango Delta is a flood driven system and much of the fish distribution throughout the Delta and the timing of certain behavioural activities are dependent on the timing and magnitude of the flood. For the purpose of determining the distribution of fish parasites throughout the system, the distribution of the fish hosts was determined and it was found that fish community structure could be used to distinguish different habitat types within the different ecological regions. Fifty-nine of the expected 68 fish species for the Delta have been collected. These species represent 12 families of which the families Cichlidae and the Cyprinidae are the most abundant, making up about 50 percent of the species collectively. Various parasites have been collected from these fishes of which the monogeneans seem to be the most prevalent and abundant and currently represent approximately 36% of the parasites collected. Most of the monogeneans recorded thus far were representatives of the subclass Polyonchoinea. Of these, all belonged to the families Dactylogyridae and Gyrodactylidae. Of the monogenean parasites infesting the Okavango fishes, the representatives of the family Dactylogyridae were the most diverse. Genera of African dactylogyrids are either endemic to Africa or belong to genera with wider geographical ranges. In general dactylogyrids are host specific and their zoo geographical affinities are therefore linked to the faunistic origin of their hosts. The distribution of dactylogyrid species within Africa is determined by the distribution pattern of their hosts. Twenty-two dactylogyrid species comprising seven genera were recorded, of these 10 species were previously undescribed. This study represents the first records of representatives of the class Monogenea from Botswana and hence the Okavango Delta.en_ZA
dc.description.abstractAfrikaans: Die Okavango Delta is baie beroemd vir die diversiteit van natuurlewe wat dit onderhou. Daar is onlangs toenemende belangstelling vir die diversiteit van visspesies wat daar voorkom. Die visse van die Okavango word as al hoe meer belangriker beskou as 'n natuurlike hulpbron wat inkomste vir Botswana se ekonomie verwerf, in die vorm van ekotourisme en akwakultuur asook as belangrike voedselbron vir die plaaslike gemeenskap. Die Okavango Delta is 'n vloedaangedrewe stelsel en die verspreiding van die visse en die tydsberekinge van sekere gedragsaktiwiteite, is van die tydsberekening en omvang van die jaarlikse vloed afhanklik. Om die verspreiding van visparasiete in die stelsel te bepaal, was die visverspreiding bepaal en daar was gevind dat visgemeeskappe gebruik kan word om tussen verskeie habitattipes binne verskillende ekologiese gebiede te onderskei. Nege-en-vyftig van die verwagte 68 visspesies vir die Delta was versamel. Hierdie spesie verteenwoordig 12 visfamilies van wie die families Cichlidae en Cyprinidae die volopste was en het sowat 50% van al die spesies opgemaak. Verskeie parasiete was van die visse versamel, waarvan teenwoordigers van die klas Monogenea blyk om die mees volopste te wees, en verteenwoordig tans 36% van die parasiete wat versamel was. Van die teenwoordigers van die Monogenea was die meeste daarvan verteenwoodigers van die subklas Polyonchoinea, waarvan almal aan die families Dactylogyridae en Gyrodactylidae behoort het. Van die verteenwoordigers van die klas Monogenea wat Okavango visse besmet, was verteenwoordigers van die familie Dactylogyridae die mees divers. Die verteenwoordigers van die Afrikagenera van die familie Dactylogyridae is óf endemies, óf behoort aan genera met wyer geografiese verspreiding. Oor die algemeen is hierdie parasiete gasheerspesifiek en hulle verspreiding is dus van hulle gashere afhanklik. Twee-en-twintig spesies verteenwoordigend van die familie Dactylogyridae was in die Okavango Delta versamel, waarvan tien van hulle onbeskryfde spesies was. Hierdie proefskrif verteenwoordig dus die eerste rekords van die verteenwoordigers van die klas Monogenea van Botswana asook die Okavango Delta.af
dc.description.sponsorshipFoundation for Research Developmenten_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectFishes -- Parasites -- Botswanaen_ZA
dc.subjectMonogenea -- Identificationen_ZA
dc.subjectMonogenea -- Botswanaen_ZA
dc.subjectThesis (Ph.D. (Zoology and Entomolgy))--University of the Free State, 2002en_ZA
dc.titleBranchial monogenean parasites (Monogenea: Dactylogyridae) of fishes from the Okavango River and Delta, Botswanaen_ZA
dc.typeThesisen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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