Dissertations / Theses on the topic 'Fishes – South Africa – Geographical distribution'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 43 dissertations / theses for your research on the topic 'Fishes – South Africa – Geographical distribution.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Sampson, Mark Robert. "Modelling the distribution and abundance of several demersal fish species on the Agulhas Bank, South Africa." Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1006207.
Full textBurger, Lynton Francois. "The distribution patterns and community structure of the Tsitsikamma rocky littoral ichthyofauna." Thesis, Rhodes University, 1991. http://hdl.handle.net/10962/d1005104.
Full textTer, Morshuizen Leslie David. "Distribution patterns of fishes in the head region of a turbid Eastern Cape estuary." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005105.
Full textChakona, Albert. "Comparative biogeography and ecology of freshwater fishes in the Breede and associated river systems, South Africa." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1015694.
Full textRobertson, Mark Peter. "Predictive modelling of species' potential geographical distributions." Thesis, Rhodes University, 2003. http://hdl.handle.net/10962/d1007189.
Full textScott, Lucy Elizabeth Powell. "The development of a geographic information systems based atlas of southern African freshwater fish, and its application to biogeographic analysis." Thesis, Rhodes University, 2000. http://hdl.handle.net/10962/d1005099.
Full textRoux, Maryanne. "The diversity and distribution patterns of intertidal fish in the Agulhas bioregion." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1019712.
Full textSelamolela, S. D. "A retrospective study on the geographical distribution of cholera in Limpopo Province, South Africa." Thesis, University of Limpopo, 2016. http://hdl.handle.net/10386/2420.
Full textIntroduction: During mid-November 2008, eleven acute watery diarrhoea cases with the suspicion of cholera like symptoms were detected by a diarrhoea surveillance system at Musina Hospital in Vhembe district - Limpopo Province, South Africa. These cases included eight Zimbabwean and three South African citizens. Laboratory test performed on stool specimens confirmed Vibrio cholerae serogroup 01 Ogawa as the causative pathogen for these reported acute watery diarrhoea cases. Within eight weeks of its onset, the outbreak spread to all the five districts of Limpopo. So far between 15 November 2008 and 01 June 2009, the cumulative number of cases of acute watery diarrhoea reported from five districts of Limpopo Province stands at 4634 including 30 confirmed cholera deaths with an overall case fatality rate of 0.65%. Of these reported cases, Vibrio cholerae has been laboratory confirmed in 656 samples. Methodology: A database was received from the Limpopo Department of Health having all reported cholera cases during the 2008 and 2009 outbreak in Limpopo Province. The data was analysed using STATA statistical software version 12 for windows (STATA Corporation, College Station, Texas). Results: The cholera affected all ages, but the geographic distribution of the disease was very heterogeneous in Limpopo Province. The highest and lowest numbers of cases were reported in Capricorn and Mopani districts, respectively. The majority of the cases 55% (N=2 542) were females. Children less than five years of age 14.2% (N=652) were less affected by the disease. About 73.8% of the cases were aged between O and 44 years. The first four weeks of cholera outbreak strictly included a day-to-day admixture of Zimbabweans and South Africans presenting in the health facilities. The outbreak then affected most South Africans after week five of the epidemic. Conclusion: The cholera outbreak has affected all the five districts of Limpopo Province in South Africa, and new cases continued to be reported until first week of June 2009. There was a link between the Zimbabwean and South African cholera outbreak in Limpopo province.
Dudley, Sheldon Francis John. "Snoek Thyrsites atun in South African waters : aspects of its biology, distribution and fishery." Master's thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/22189.
Full textThe snoek Thyrsites atun is an important fish predator in the southern Benguela region. It is exploited by both a handline and a demersal fishery. A survey of the Cape line fishery revealed that snoek line fishing effort is changing from the traditional harbour-based line-boat to the nomadic ski-boat. It was widely claimed that snoek catches are declining and that migration patterns are changing. Snoek constitute a by-catch of the hake-directed demersal fishery but nevertheless are seasonally important. The principle prey of snoek caught by handline off the Cape Peninsula were anchovy and mantis shrimp. Snoek caught in midwater trawls offshore were feeding primarily on anchovy, with pilchard, euphausiids and amphipods also important. Snoek trawled demersally had a more diverse diet, dominated by redeye roundberring, lightfish, lanternfish, hake, buttersnoek and euphausiids. Snoek were caught in the demersal environment throughout daylight hours, but may come off the bottom at night. The small degree of overlap between the diet of snoek caught demersally offshore and that of snoek caught in the pelagic zone, both inshore and offshore, indicates that snoek do not seem to move extensively on a diurnal basis between the two zones. Over the period 1970 to 1985 availability of snoek to the handline fishery was strongly seasonal, with catches peaking from May to July, although the traditional winter snoek run is a declining phenomenon along the South African coast. At Dassen Island, for which catch data have only been available since 1981, peak months were from November to January. The snoek seems to move offshore from July and is trawled demersally until September. The presence of snoek larvae offshore between June and September indicates an offshore spawning migration. With the exception of the summer presence in the region of Dassen Island, snoek appear to be present in the southern Benguela region between April and September. Handline catches of snoek have declined markedly since 1978, but demersal catches have remained more stable.
Bates, Michael Francis. "An analysis of the Pseudocordylus melanotus complex (Sauria: Cordylidae)." Thesis, Stellenbosch : Stellenbosch University, 2007. http://hdl.handle.net/10019.1/21451.
Full textENGLISH ABSTRACT: The taxonomic status of southern Africa’s rupicolous crag lizards (genus Pseudocordylus) was investigated. As considerable confusion exists in the literature regarding the type specimens and type localities of the various taxa, resolution of these problems were considered the starting point of the study. Examination of museum specimens allowed for the designation of lectotypes, alloparalectotypes and/or paralectotypes. Of particular relevance to this study was the rediscovery of Andrew Smith’s type specimens of P. m. melanotus and P. m. subviridis. Restriction of the type locality of P. m. subviridis, based on entries in Smith’s diary and journal, allowed for the confirmation of previous interpretations and definitions of the two taxa. The geographical distribution of the various taxa and populations was determined using an extensive locality database. Two kinds of molecular markers, namely allozymes and mitochondrial DNA, were used in an attempt to resolve taxon boundaries within the P. melanotus species complex. The allozyme analysis indicated that P. m. melanotus might be polyphyletic and comprised of two unrelated lineages. Furthermore, fixed allelic differences between parapatric populations of P. m. melanotus and P. m. subviridis, and between sympatric populations of P. m. subviridis and P. langi, suggested that all three forms might be considered full species, with the possibility of more cryptic species present in the complex. Pseudocordylus transvaalensis differed from most other populations by 1-3 fixed allelic differences, but was indistinguishable from the Nkandhla district (central KwaZulu-Natal) population of P. m. melanotus. There were no heterozygous individuals in a sample from Monontsha Pass (Qwa-Qwa), a population reportedly comprising P. m. melanotus and P. m. subviridis, as well as intermediates, and all specimens were assignable to P. m. subviridis. The allozyme study was, however, based on phenetic principles and for further taxonomic resolution a cladistic approach was required. An mtDNA analysis (16S rRNA gene) using Maximum Parsimony, Maximum Likelihood and Bayesian analyses was therefore conducted to determine phylogenetic relationships among species and subspecies and to re-assess the taxonomic status of forms in the P. melanotus species complex. The mtDNA analysis corroborated most of the results obtained in the allozyme analysis. Firstly, P. langi was again found to be basal. With the addition of P. microlepidotus and P. spinosus to the ingroup, it is now apparent that P. langi is the basal species in the genus. (Recent studies have indicated that P. capensis and P. nebulosus are not congeneric with Pseudocordylus.) Secondly, the 16S rRNA results confirm that P. m. melanotus, as presently construed, is comprised of two clades that are not sister groups. The northern populations of P. m. melanotus (Sabie and Lochiel) form a fairly deeply divergent clade that may represent a separate species. The Nkandla population was, however, found to cluster with the other southern P. m. melanotus populations and not with P. transvaalensis as was the case in the allozyme electrophoretic analysis. However, the most surprising result of the 16S rRNA analysis was the finding that both P. microlepidotus and P. spinosus are embedded within P. m. subviridis. This suggests that these two species evolved from within P. m. subviridis and may have been separated only recently, with rapid morphological divergence occurring, but with limited genetic differentiation. It is suggested that all of the above three taxa be provisionally treated as full species. There was also morphological support for the uniqueness of all groupings indicated by the mtDNA analysis. Pseudocordylus transvaalensis is characterized by its large size, unique dorsal and gular (black) colour patterns, as many as three horizontal rows of lateral temporal scales, a series of small scales posterior to the interparietal scale, and usually two subocular scales behind the median subocular on either side of the head. The various populations currently classified under the name P. melanotus are more difficult to separate, but P. m. melanotus and P. m. subviridis usually differ as follows: frontonasal divided in P. m. melanotus, undivided in P. m. subviridis (and most Northern melanotus); lateral temporals in two rows, upper more elongate versus single row of much elongated scales; longitudinal rows of dorsolaterals closely-set versus widely separated; femoral pores of females pit-like versus deep with secretory plug. Northern melanotus differs from Southern melanotus in usually having an undivided frontonasal scale and seldom having a small scale present behind the frontonasal. Pseudocordylus langi has unique dorsal and gular colour patterns (including a series of blue spots on the flanks), granular dorsals with 6-9 paravertebral rows of enlarged flat scales, high total numbers of femoral pores (25-34) and usually only five (smooth not keeled or ridged) infralabial scales on either side of the head. Pseudocordylus spinosus also has unique dorsal and gular colour patterns, spinose lateral scales, frontonasal longer than wide and excluded from the loreal scales, low total femoral pore counts (6-9), and females (not only males) have differentiated femoral scales. Both Principal Components Analysis (PCA) and Canonical Discriminant Analysis (CDA) distinguished four groups, namely P. transvaalensis, P. langi, P. spinosus and a P. melanotus/subviridis/microlepidotus cluster. A separate CDA of all P. melanotus populations partly distinguished between Southern melanotus and P. m. subviridis, and largely separated Northern melanotus; whereas a CDA of P. transvaalensis showed that all three allopatric populations are 100% distinguishable in morphological space. A Nested Clade Analysis indicated that fragmentation as well as range expansion played a role in the distribution of the P. melanotus species complex. This may be explained by climatic oscillations (high-low temperatures and wet-dry cycles) during the Cenozoic that caused habitat expansion and contraction. Based on the topology of the mtDNA phylogram it is apparent that the genus Pseudocordylus originated along the eastern escarpment. A P. langi-like ancestor may have had an extensive range along the eastern escarpment, with the Maloti-Drakensberg forming the southern limit of its range. During a subsequent rise in global temperatures, range contraction and fragmentation took place, leaving an isolated population in the south and one in the north. The southern population survived unchanged in the Maloti-Drakensberg refugium, but the northern population was forced to adapt to the warmer conditions. Thereafter, the northern form expanded its range again, but during a subsequent cooler period, range contraction occurred, resulting in an isolated north-eastern population in the Sabie-Lochiel area in Mpumulanga (Northern melanotus) and a western population. Relationships in the latter clade are not sufficiently resolved to allow further reconstruction of biogeographic history, but it is clear that a P. m. subviridis-like form became isolated in the south where it eventually came into contact with P. langi at high elevations. Pseudocordylus m. subviridis eventually extended its range southwestwards into the inland mountains of the Eastern Cape and Cape Fold Mountains to give rise to the P. microlepidotus complex. This cycle of range expansion and contraction may also account for the isolated populations at Suikerbosrand, Nkandhla district, and in the Amatole-Great Winterberg mountain region. Furthermore, it is suggested that P. spinosus originated from a P. m. subviridis-like ancestral population that became isolated on the lower slopes of the Drakensberg where terrestrial predation pressure resulted in a quick shift in morphology from fairly smooth body scales to a more spiny morphology.
AFRIKAANSE OPSOMMING: Die taksonomiese status van suidelike Afrika se rotsbewonende krans-akkedisse (genus Pseudocordylus) is ondersoek. Omdat daar aansienlike verwarring in die literatuur bestaan met betrekking tot die tipe monsters en die tipe lokaliteite van die verskillende taksa, is die oplossing van hierdie probleme as die beginpunt van hierdie studie geneem. Die bestudering van akkedismonsters in museums het dit moontlik gemaak om lektotipes, alloparalektotipes en/of paralektotipes aan te wys. Van besondere belang vir hierdie studie is die herontdekking van Andrew Smith se tipe monsters van P. m. melanotus en P. m. subviridis. Die beperking van die tipe lokaliteit van P. m. subviridis, gebaseer op inskrywings in Smith se dagboek en joernaal, het dit moontlik gemaak om vorige interpretasies en definisies van die twee taksa te bevestig. Die geografiese verspreiding van die verskillende taksa en bevolkings is bepaal deur middel van ’n omvattende lokaliteit databasis. Twee soorte molekulêre merkers, naamlik allosieme en mitokondriale DNS, is gebruik in ʼn poging om uitsluitsel te verkry oor die takson-grense binne die P. melanotus-spesiekompleks. Die allosiem-analise het daarop gedui dat P. m. melanotus moontlik polifileties mag wees en uit twee onverwante stamboom-vertakkings kan bestaan. Verder het vaste alleliese verskille tussen parapatriese bevolkings van P. m. melanotus en P. m. subviridis, en tussen simpatriese bevolkings van P. m. subviridis en P. langi, daarop gedui dat al drie vorme as volledige spesies beskou kan word, met die moontlikheid dat meer kriptiese spesies in die kompleks teenwoordig kan wees. Pseudocordylus transvaalensis het van die meeste ander bevolkings verskil met 1-3 vaste alleliese verskille, maar was ononderskeibaar van die bevolking van P. m. melanotus van die Nkandhla distrik (sentraal KwaZulu-Natal). Daar was slegs homosigote individue in ʼn steekproef van Monontsha Pas (Qwa-Qwa), ʼn bevolking wat volgens die literatuur P. m. melanotus en P. m. subviridis, sowel as intermediêre omvat, en alle monsters was toekenbaar aan P. m. subviridis. Die allosiemstudie is egter gebaseer op fenetiese beginsels en vir verdere taksonomiese oplossing is ʼn kladistiese benadering vereis. ʼn Mitokondriale DNS-analise (16S rRNS geen) wat gebruik maak van Maksimum Parsimonie-, Maksimum Waarskynlikheids- en Bayes-analises is daarom uitgevoer om die filogenetiese verwantskappe tussen spesies en subspesies te bepaal en om die taksonomiese status van vorme in die P. melanotus-spesiekompleks te herondersoek. Die mtDNS-analise het die meeste van die resultate van die allosiem-analise bevestig. Eerstens, P. langi is weer bevind om basaal te wees. Met die byvoeging van P. microlepidotus en P. spinosus tot die binne-groep het dit nou duidelik geword dat P. langi die basale spesie in die genus is. (Onlangse studies het aangedui dat P. capensis en P. nebulosus nie kongeneries met Pseudocordylus is nie.) Tweedens, die 16S rRNS resultate bevestig dat P. m. melanotus, soos tans vasgestel, saamgestel is uit twee klade wat nie sustergroepe is nie. Die noordelike bevolkings van P. m. melanotus (Sabie en Lochiel) vorm ʼn redelik diep divergente klaad wat ʼn afsonderlike spesie mag verteenwoordig. Dit is egter bevind dat die Nkandla bevolking saamgegroepeer het met die ander suidelike P. m. melanotus-bevolkings en nie met P. transvaalensis soos wat die geval was in die allosiem-elektroforetiese analise nie. Die mees verbasende resultaat van die 16S rRNS-analise was egter die bevinding dat beide P. microlepidotus en P. spinosus genestel was binne P. m. subviridis. Dit dui daarop dat hierdie twee spesies kon ontwikkel het vanuit P. m. subviridis en slegs onlangs van mekaar geskei het, toe vinnige morfologiese splitsing voorgekom het, maar met beperkte genetiese differensiasie. Dit word voorgestel dat al drie die bogenoemde taksa voorlopig as volledige spesies beskou word. Daar was ook morfologiese steun vir die uniekheid van al die groeperings wat die mtDNS-analise uitgewys het. Pseudocordylus transvaalensis kan uitgeken word aan sy bogemiddelde grootte, unieke dorsale en (swart) kleurpatrone op die keel, so veel as drie horisontale rye lateraaltemporale skubbe, ʼn reeks klein skubbe agter die interpariëtale skub, en gewoonlik twee subokulêre skubbe agter die middelste subokulêre skub op beide kante van die kop. Die verskillende bevolkings wat tans geklassifiseer word as P. melanotus is moeiliker om van mekaar te skei, maar P. m. melanotus en P. m. subviridis verskil gewoonlik soos volg: frontonasale skub in twee gedeel in P. m. melanotus, heel in P. m. subviridis (en in die meeste Noordelike melanotus); lateraal-temporale skubbe in twee rye, die boonste ry met verlengde skubbe teenoor ʼn enkele ry verlengde skubbe; longitudinale rye van dorsolaterale skubbe naby aan mekaar teenoor ver uit mekaar; femorale porieë van wyfies klein en vlak teenoor diep met sekreterende proppe. Noordelike melanotus verskil van Suidelike melanotus deurdat hulle gewoonlik ʼn heel frontonasale skub het en daar selde ʼn klein skub teenwoordig is agter die frontonasale skub. Pseudocordylus langi het unieke dorsale en keel-kleurpatrone (wat ʼn reeks blou kolle op die sye insluit), granulêre dorsale skubbe met 6-9 rye vergrote plat skubbe langs die rugsteen, ʼn groot totale aantal femorale porieë (25-34), en gewoonlik net vyf (glad, ongerif) infralabiale skubbe op elke kant van die kop. Pseudocordylus spinosus het ook unieke dorsale en keel-kleurpatrone, skerp laterale skubbe, frontonasale skub langer as wyd en nie in kontak met die loreale skubbe nie, klein totale aantal femorale porieë (6-9), en wyfies (nie net mannetjies nie) het gedifferensieerde femorale skubbe. Die Hoof-komponent Analise (HKA) en die Kanonieke Diskriminant Analise (KDA) het albei vier groepe geïdentifiseer, naamlik P. transvaalensis, P. langi, P. spinosus en ʼn P. melanotus/subviridis/microlepidotus groepering. ʼn Aparte KDA van alle P. melanotus bevolkings het gedeeltelik onderskei tussen Suidelike melanotus en P. m. subviridis, en die Noordelike melanotus is grootliks van die ander onderskei; terwyl ʼn KDA van P. transvaalensis daarop gedui het dat al drie allopatriese bevolkings 100% onderskeibaar in morfologiese ruimte is. ʼn Genestelde Klaad-Analise het aangedui dat fragmentasie, sowel as gebiedsuitbreiding, ʼn rol gespeel het in die verspreiding van die P. melanotus-spesiekompleks. Dit kan moontlik verklaar word deur die klimaatswisselinge (hoë-lae temperature en nat-droë siklusse) gedurende die Senosoikum wat habitat-uitbreiding en –verkleining veroorsaak het. Gebaseer op die topologie van die mtDNS filogram is dit duidelik dat die genus Pseudocordylus al langs die oostelike platorand ontstaan het. ʼn Voorouer soortgelyk aan P. langi kon ʼn uitgebreide gebied al langs die oostelike platorand gehad het, met die Maloti-Drakensberg wat die suidelike limiet van hierdie gebied gevorm het. Gedurende ʼn daaropvolgende toename in globale temperature het gebiedsverkleining en fragmentasie plaasgevind, wat ʼn geïsoleerde bevolking in die suide en een in die noorde tot gevolg gehad het. Die suidelike bevolking het onveranderd oorleef in die Maloti-Drakensberg skuilplek (“refugium”), maar die noordelike bevolking is geforseer om aan te pas in die warmer toestande. Daarna het die noordelike vorm se gebied weer uitgebrei, maar gedurende ʼn daaropvolgende koeler periode het gebiedsverkleining weer plaasgevind, met die gevolg dat daar ʼn geïsoleerde noord-oostelike bevolking in die Sabie-Lochiel-area in Mpumalanga (Noordelike melanotus) en ʼn bevolking in die weste was. Verwantskappe in die laasgenoemde klaad is nie voldoende opgelos om verdere rekonstruksie van die biogeografiese geskiedenis moontlik te maak nie, maar dit is duidelik dat ʼn vorm soortgelyk aan P. m. subviridis geïsoleer geraak het in die suide waar dit eindelik op hoë liggings in kontak gekom het met P. langi. Die gebied van P. m. subviridis is ook later suidweswaarts uitgebrei tot in die binnelandse berge van die Oos-Kaap en Kaapse Plooiberge om tot die ontstaan van die P. microlepidotuskompleks aanleiding te gee. Hierdie siklus van gebiedsuitbreiding en verkleining kan ook ʼn verklaring bied vir die geïsoleerde bevolkings by Suikerbosrand, Nkandhla distrik, en in die Amatole-Groot Winterberg-streek. Verder word voorgestel dat P. spinosus ontstaan het uit ʼn voorouerlike bevolking soortgelyk aan P. m. subviridis wat geïsoleerd geraak het op die laer hange van die Drakensberg waar die druk van aardsbewonende roofdiere tot ʼn vinnige verandering in morfologie vanaf redelik gladde liggaamskubbe tot ʼn meer skerppuntige morfologie gelei het.
Swart, Belinda. "The phylogeography of the southern rock agama (Agama atra) in the Cape Fold Mountains, South Africa." Thesis, Stellenbosch : Stellenbosch University, 2006. http://hdl.handle.net/10019.1/21762.
Full textENGLISH ABSTRACT: An understanding of the phylogeography and evolutionary processes involved in speciation is essential for the conservation and management of any particular species. To investigate the phylogeographic patterns in Agama atra from the Cape Fold Mountains (CFM), 98 individuals from 38 geographically close localities were analysed. In addition, to understand the phylogeographic associations between the CFM populations and the rest of Southern Africa, 18 specimens from 12 localities outside the CFM were also included. A total of 988 characters derived from two mitochondrial DNA fragments (control region and ND2) revealed 59 distinct haplotypes in the CFM. Parsimony, Bayesian and maximum likelihood analyses revealed four distinct clades associated with geography within the CFM. These clades were supported by a haplotype network and were defined as the Cape Peninsula clade, the Limietberg clade, the northern CFM clade and the central CFM clade. Analysis of molecular variance confirmed the high degree of genetic structure within the CFM, with more than 75% of genetic variation found among the geographic areas. SAMOVA and nested clade analysis (NCA) suggest that the central CFM clade may be more diverse than detected by the networks and the phylogenetic analyses. The processes that caused the four distinct genetic groups in the CFM are not yet clear. Using a speculative molecular clock estimate, the main cladogenesis of A. atra within the CFM took place, approximately ~6.5 - 9 MYA. This dating coincides well with the documented Miocene-Pliocene climate fluctuations which might have contributed towards the isolation among lineages. The genetic structure found in A. atra is also markedly congruent with what has been found in other taxa such as Mesamphisopus spesies, Potamonautes brincki, and Pedioplanis burchelli and this would further support vicariance as a main isolating factor here.
AFRIKAANSE OPSOMMING: ‘n Goeie begrip van die filogeografie en die evolusionêre gebeurtenisse wat verband hou met spesiasie is belangrik vir die bewaring en bestuur van enige spesie. Om die filogeografiese patrone in Agama atra van die Kaapse Plooiberge (KPB) te ontleed, was 98 individue van 38 nabygeleë lokaliteite geanaliseer. Tesame met bogenoemde monsters was 18 individue van 12 lokaliteite van buite die KPB ook geanaliseer om die filogeografiese verwantskappe tussen die KPB bevolkings en die res van Suidelike Afrika te ondersoek. Uit ‘n totaal van 988 karakters verkry uit twee mitochondriale DNS fragmente (die kontrole gebied en ND2) is 59 haplotipes gevind. Parsimonie en modelgebaseerde filogenetiese analises dui daarop dat vier groepe geassosieer met geografie binne die KPB voorkom. Die groepe word geondersteun deur ‘n haplotipe netwerk en word soos volg gedefinieer: ‘n Kaapse Peninsula groep, ‘n Limietberg groep, ‘n noordelike KPB groep en ‘n sentrale KPB groep. Analises van molekulêre variansie (AMOVA) bevestig die hoë graad van genetiese struktuur binne die KPB, met meer as 75% genetiese variasie gevind tussen die geografiese areas. SAMOVA en gesetelde groep analises (“NCA”) stel voor dat die sentrale KPB groep dalk meer variasie vertoon as wat die netwerk en filogenetiese analises vertoon. Die prosesse wat die vier genetiese groepe tot stand gebring het is nog nie bekend nie. Volgens ‘n spekulatiewe molekulêre klok berekening het die hoof kladogenese van A. atra binne die KPB ongeveer ~6.5 - 9 miljoen jaar (MJ) gelede plaasgevind. Hierdie datering stem goed ooreen met die gedokumenteerde Mioseen-Plioseen klimaat veranderinge wat isolasie van die groepe kon bewerkstellig het. Die genetiese struktuur van A. atra in the KPB is ook gevind in ander taksa soos Mesamphisopus spesies, Potamonautes brincki, en Pedioplanis burchelli en bevestig dus dat vikariansie hier die hoof faktor vir isolasie is.
Purchase, David Bryce. "Patterns of distribution, abundance and community composition of rock pool fishes in Goukamma Nature Reserve, South Africa." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/28158.
Full textRabali, Ridovhusanae. "Availability of registered pharmaceutical structures in South Africa : 2003 until 2008 / Ridovhusanae Rabali." Thesis, North-West University, 2009. http://hdl.handle.net/10394/4271.
Full textThesis (M.Pharm. (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2010.
Lotter, Johanna Magdalena. "Potential implications of climate change for Rooibos (A. linearis) production and distribution in the greater Cederberg region, South Africa." Doctoral thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/15585.
Full textWild plants assist in supporting human livelihoods worldwide, both within traditional systems of medicine, and as economically useful plants. Indigenous to the Fynbos biome in the north-western part of the Western Cape, South Africa is the leguminous shrub, A. linearis (rooibos), which is extensively used as ethnomedicine by local communities, while also commercially grown and exported for the herbal tea market. Being a range-restricted species, climate change poses a threat to wild plants and their dependent communities, as well as the sustainability of the rooibos industry. Climate mediated impacts on rooibos are mostly substantiated by anecdotal evidence from commercial growers and local communities and have traditionally been insufficiently addressed. This study integrates predictive modelling and empirical data to provide important insights into rooibos' plant physiological functioning in the presence of climatic and environmental constraints. The aim is to determine whether there is evidence of climate change over the rooibos distribution area, how these climate anomalies are expected to affect the species distribution and to perform experimental studies by testing plant physiological functioning of A. linearis under changing climate conditions. Analysis of climate parameters important for rooibos production (rainfall frequency and intensity, temperature extremes and wind speed) have shown that plants will experience a shorter period of water availability during winter, and prolonged exposure to summer conditions (high temperatures and water stress) in the coming decades. Under these conditions, climate envelope modelling suggests that wild and cultivated rooibos types are at risk to lose between 49.8% and 88.7% in the extent of the bio-climatically suitable localities, most notably along the western and northern periphery of the rooibos production area by 2070. Plant physiological responses (growth analysis, gas exchange parameters and leaf carbon and nitrogen isotope ratios) to the assessed climate anomalies were measured in experimental studies at glasshouse and field scale. Specific adaptation mechanisms (increasing water use efficiency, developing a higher level of sclerophylly and altering the allocation of plant reserves) which helped seedlings to survive short term drought in the glasshouse were not able to offset more severe conditions in field settings. Finally, a comparison of wild and cultivated tea has shown an apparent adaptive advantage of wild tea to tolerate increased aridity with greater water economy, and more reliance on biological nitrogen fixation for N nutrition, indicating a potentially less severe scenario of range contraction for wild types than initially indicated. This study provides a more robust prediction of rooibos plant responses to climate change factors to enable more effective adaptive planning and conservation management in a changing climate.
Gouws, Gavin. "The biogeography, systematics and conservation of Phreatoicidean isopods in South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16052.
Full textENGLISH ABSTRACT: Historically, isopods of the suborder Phreatoicidea were thought to be represented in southern Africa by four species belonging to the endemic genus Mesamphisopus. This taxonomy was based on poor collections and the extent of variation among and within populations were poorly understood. In the present study, intensive sampling was undertaken to determine the diversity, distribution and biogeography of phreatoicidean isopods within South Africa. Analyses of allozyme data and mitochondrial DNA sequences (from the 12S rRNA and protein-coding COI genes) were used to examine differentiation among populations, extricate species boundaries (in combination with morphometric and morphological data) and to elucidate the evolutionary relationships among taxa. Additionally, conservation units were identified among the sampled populations and conservation threats highlighted. First, genetic and morphometric differentiation was examined among populations identified morphologically as M. capensis. Collection localities spanned two mountainous regions in the Western Cape and these were separated by a coastal plain remnant. Five morphometrically and genetically distinct species were identified. These taxa are also geographically partitioned in two regions, which were regarded as Evolutionarily Significant Units. Differentiation among populations of the two regions, and similar patterns in other taxa, was attributed to Cenozoic sea-level fluctuations. Second, populations, variably assigned to M. abbreviatus or M. depressus, were examined to determine whether they were conspecific. A large geographic area was sampled to account for intraspecific differentiation. Limited morphometric discrepancies were observed, with individual populations being either similar to the M. abbreviatus or the M. depressus syntypes. Genetic support for the recognition of a cryptic species complex among the sampled populations was equivocal. Substantial genetic differentiation and a lack of gene flow were observed among all populations. Clear patterns of isolation by distance were not detected, and genetic structure appeared to be unrelated to geography or drainage systems. The mosaic pattern of relatedness among populations was best explained by stochastic demographic processes, such as extinction-recolonization events or population bottlenecks.Thirdly, detailed taxonomic descriptions and illustrations of six new species, identified genetically and morphometrically among the populations included in the above analyses, were provided. These species were largely distinguished from each other, and the four original species, using a combination of setation, mouthpart, pleopod and uropod features. Lastly, phylogenetic relationships among all ten recognized Mesamphisopus species, and an additional unresolved group of populations, were examined. MtDNA data partitions and a recoded allele frequency matrix were analysed independently and in combination. Topologies indicated unrecognized species-diversity within an unresolved group of populations. Evolutionary relationships, the identification of six biogeographic centres, and the dating of divergences using a relaxed Bayesian clock suggested that differentiation and speciation within Mesamphisopus was largely allopatric or vicariant and driven by Mesozoic sea-level and climate change. Chance long distance dispersal events would, in turn, explain spurious phylogenetic relationships and distributions. This study contributes significantly to the understanding of the diversity and the conservation of the little-studied southern African freshwater invertebrates. Moreover, this study is the first to investigate genetic and morphometric differentiation, and phylogenetic relationships, below the generic level within the Phreatoicidea; thus establishing a methodological and theoretical framework for species delineation and the accurate determination of biodiversity within individual phreatoicidean genera.
AFRIKAANSE OPSOMMING: Isopoda van die suborder Phreatoicidea was histories in suidelike Afrika verteenwoordig deur vier spesies wat almal aan die endemiese genus Mesamphisopus behoort. Hierdie taksonomie is op ’n beperkte hoeveelheid versamelings gebaseer en die omvang van variasie tussen (en binne) bevolkings was swak verstaan. In die huidige studie is ekstensiewe versameling onderneem om die verspreiding, diversiteit asook biogeografie van dié Isopoda in Suid Afrika te bepaal. Analises van allosiem data en mitokondriale DNS volgorderbepalings (van die 12S rRNS en die proteïenkoderende COI geen) was gebruik om differensiasie tussen bevolkings te ondersoek, om (in kombinasie met morfometriese en morfologiese data) spesiesgrense te bepaal asook om die evolusionêre-verwantskappe tussen taksa te definieer. Benewens word bewaringseenhede binne die studie-bevolkings geïndentifiseer en moontlike bedreigings uitgelig. Eerstens is genetiese en morfometriese differensiasie tussen bevolkings, wat as M. capensis geïdentifiseer is, ondersoek. Versamelingslokaliteite was versprei oor twee bergagtige streke in die Weskaap wat geskei word deur ’n voormalige kusvlakte. Vyf morfometries- en geneties-afsonderlike spesies is geïdentifiseer. Dié taksa was geografies geskei tot die twee streke, wat elk as ’n Evolusionêre Beduidende Eenheid (ESU) gesien kan word. Differensiasie tussen populasies van die twee streke en vergelykbare patrone binne ander taksa word aan Cenosoïese seevlak veranderings toegeskryf. Tweedens is bevolkings wat as M. abbreviatus óf as M. depressus geïdentifiseer kan word ondersoek om te bepaal of hulle konspesifiek is. Bevolkings is oor ’n groot geografiese gebied versamel om intraspesifieke variasie in aanmerking te neem. Beperkte morfometriese verskille is waargeneem – enkel bevolkings was morfometries identies aan of die M. abbreviatus of die M. depressus sintipes. Genetiese getuienis vir die herkenning van ’n kriptiese spesieskompleks was dubbelsinnig. Bevolkings is gekenmerk deur merkbare genetiese differensiasie en die afwesigheid van geenvloei. Duidelike bewys van isolasie-metafstand was nie waargeneem nie en genetiese struktuur was nie verwant aan geografiese ligging of riviersisteme nie. Die mosaïese patroon van verwantskappe is moontlik teweeg gebring deur stogastiese demografiese prosesse soos uitsterwing en hervestiging of deur afnames in bevolkingsgrootte.Derdens is omvattende taksnomiese beskrywings en illustrasies van ses nuwe spesies wat deur bogenoemde analises geneties en morfometries uitgelig was, verskaf. Dié spesies is van mekaar, asook die ander vier spesies onderskeibaar deur ’n kombinasie van setasie-, monddeel-, pleiopoot- en uropooteienskappe. Laastens is die filogenetiese verwantskappe tussen al tien herkende Mesamphisopus-spesies en ’n groep bevolkings waarvan verhoudings onseker was, ondersoek. MtDNS datastelle en ’n hergekodeerde alleelfrekwensie matriks is afsonderlike en in kombinasie geanaliseer. Topologië het onherkende spesies-vlak diversiteit binne die bogenoemde groep bevolkings aangedui. Evolusionêre verwantskappe, die herkenning van ses biogeografiese gebiede, en die bepaling van tye van divergensie (d.m.v. ’n ontspanne Bayesiaanse molekulêre klok) het aangetoon dat spesiasie binne Mesamphisopus grootliks allopatries was en deur Mesosoïese seevlak- en klimaatsveranderings teweeg gebring is. Toevallige lang-aftstand verspreiding kon dan eienaardige filogenetiese verhoudings en verspreidings verklaar. Dié studie lewer ’n wesenlike bydrae tot die kennis van die diversiteit en tot die bewaring van die onbestudeerde Suid Afrikaanse varswater ongewerweldes. Daarenbowe, is hierdie studie die eerste om genetiese en morfometriese differensiasie benede die genusvlak binne die Phreatoicidea te ondersoek; sodoende word die metodologiese en teoretiese raamwerk vir die herkenning van spesies en die akkurate beskrywing van diversiteit binne afsonderlike genera van die Phreatoicidea geskep.
Weimann, Amy. "The use and disaggregation of survey data to study the cross-sectional and spatial distribution of multimorbidity and its association with socioeconomic disadvantage in South Africa." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/22926.
Full textDuncan, Murray. "The genetic stock structure and distribution of Chrysoblephus Puniceus, a commercially important transboundary linefish species, endemic to the South West Indian Ocean." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1011868.
Full textMeyer, Anita. "The relevance of the Greater Cederberg Biodiversity Corridor (GCBC) for reptile conservation." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/21676.
Full textENGLISH ABSTRACT: The Greater Cederberg Biodiversity Corridor (GCBC) is a large-scale conservation corridor situated in the south-western region of South Africa. Delineation of the GCBC was largely based on by vegetation data. The relevance of the GCBC for the conservation of the reptilian fauna in the area south of 31°S and west of 21°E is assessed in the present study. This entailed determining the GCBC’s coverage of regional reptile diversity patterns and assessing its potential conservation significance during possible climate induced changes in reptile distributions. Reptile species point distribution data from the preliminary (2007) SARCA (South African Reptile Conservation Assessment) database was used. Under-representation of the Tankwa Karoo in the dataset required a field survey of this region. Additionally, the biogeographical influence of the arid Tankwa Karoo Basin on the distribution of reptiles in the south-western districts of South Africa was investigated. Turnover across the Basin is high, species richness is lower than in surrounding mountainous areas and there are no species endemic to the area. The Tankwa Karoo Basin acts as a dispersal barrier for many reptile species occurring in the surrounding more mesic areas. At the same time, the ranges of a number of typical northern, arid adapted species extend southward along the Tankwa Plains. A number of species range extensions in the region are reported. Patterns of endemism, species richness and turnover were plotted from the point distribution data at quarter and eighth degree square resolution. Extensive sampling bias towards reserves and populated areas is apparent from the reptile species richness plots. This pattern is more pronounced for snakes than lizards. Reptile richness is particularly high along the north-south section of the Cape Fold Mountains and also relatively high along the south-western coast, peaking in the Lambert’s Bay area. The majority of the 20 reptile species endemic to the study area are associated with one of two identified centres of endemism: the Greater Cederberg area, or the narrow coastal zone stretching from the Lambert’s Bay area to the Cape Peninsula. An additional third set of endemics comprised of melanistic forms restricted to a number of different refugia, notably, Landroskop, the Cape Peninsula, Sladanha-Langebaan region, Piketberg Mountains and a confined area along the western section of the Cape Fold Mountains. Species richness and endemism patterns co-vary within the study area. Biotic regions were identified through hierarchical clustering of grid cells according to shared species occurrences. A Northern, Southern, Central and Western biotic region was identified. Classification tree methodology (CART) and Canonical Correspondence Analysis (CCA) were used to characterise defined biotic regions in terms of selected environmental variables. Four sets of species assemblages are described on the basis of these biotic regions – two major and two minor ones. Of the major assemblages the Northern assemblage can be described as an arid zone one and the Southern assemblage as a mesic zone one. The minor Central assemblage, comprising mainly rock-dwelling forms, represent evolutionary leftovers as a result of climate change induces cycles of contraction and expansion of arid and mesic faunas. The other minor one, the West Coast assemblage could be considered a sub-assemblage of the Northern one, with particular adaptation to the coastal climate. Environmental characterisation of the biotic regions reveals that these groupings are supported by an environmental signal. The contiguity of four distinct sets of reptiles, each with its own set of environmental requirements, in this relatively small geographic area clearly indicates that the southwestern region of South Africa is biogeographically complex. The GCBC incorporates the largely coinciding centres of endemism and richness along the West Coast and the greater Cederberg area. Although the centre of endemism for melanistic reptile forms, in the Saldanha-Langebaan area, falls just south of the GCBC boundary, the Corridor fulfils the requirements for effective conservation of reptiles in the area to a large degree. The north-south dispersal pathways provided by the Corridor along the Cape Fold Mountains is believed to be adequate to buffer climate change effects, however there is concern about its ability to contribute to the persistence of the assemblage associated with the narrow coastal zone in the west.
AFRIKAANSE OPSOMMING: Die Groter Cederberg Biodiversiteit Korridor (GCBK) is ‘n grootskaalse bewaringskorridor wat in die suid-westelike deel van Suid-Afrika geleë is. Die grense van GCBK is gebasseer op plantegroei data. In die huidige studie word die betekenis van die GCBK vir die bewaring van die reptiel fauna in die gebied suid van 31°S en wes van 21°O assesseer. Die mate waartoe die GCBK die patrone van reptieldiversiteit in die streek inkorporeer, asook die korridor se potensiaal om voorsiening te maak vir reptiel verspreidingsgebiede wat moontlik as gevolg van potensiële omgewingsverandering kan verskuif. Die beskikbare puntverspreidingsdata van die voorlopige (2007) SARCA (South African Reptile Conservation Assessment) databasis is gebruik. Swak verteenwoordiging van die Tankwa Karoo in die datastel het ‘n veldopname van die gebied genoodsaak. Verder is die biogeografiese invloed van die ariede Tankwa Karoo Kom op die verspreidingspatrone van reptiele in die suid-westelike deel van Suid-Afrika ook ondersoek. Die spesie omset van beide Noord na Suid en Wes na Oos oor die Tankwa is hoog, die spesierykheid is aansienlik laer as in die omringende bergagtige gebiede en daar is geen spesies wat endemies is tot die Tankwa Karoo nie. Die Tankwa Karoo Kom dien as ‘n barieêre teen spreiding vir sommige reptielspesies wat in die omringende gematigde gebiede voorkom. Terselfdertyd reik die verspreidings van ‘n aantal tipiese droogte aangepasde spesies vanuit die noorde suidwaarts langs die Tankwa Vlaktes. Nuwe verspredingsrekords wat ‘n paar spesies se gebiede uitbrei word ook raporteer. Die puntverspreidingsdata is geruik om die patrone van endemisme, spesierykheid en omset op kwart- en agtstegraad resolusie te plot. Spesierykheid kaarte toon ‘n duidelike neiging tot deegliker opnames in reservate en bewoonde gebiede. Hierdie patroon is meer opmerklik vir slange as akkedisse. Reptielrykheid is besonders hoog langs die noord-suid as van die Kaapse Plooiberge en ook relatief hoog langs die suid-wes kus met ‘n maksimum in die Lambertsbaai omgewing. Die meerderheid van die 20 reptielspesies wat endemies is aan die studie area is met een van twee geïdentifiseerde sentrums van endemisme geassosieer: die Groter Cederberg area óf die nou kussone wat vanaf Lambertsbaai tot Kaappunt strek. ‘n Derde stel endemiese spesies wat uit melanistiese vorme bestaan, is beperk tot ‘n aantal refugia, naamlik, Landroskop, Kaappunt, Saldanha- Langebaan omgewing, Piketberg berge en ‘n beperkte area langs die westelike dele van die Kaapse Plooiberge. Spesierykheid en endemisme patrone stem grootliks ooreen binne die studie area. Roosterselle is op grond van gedeelde spesiesamestellings met behulp van ‘n hieragiese groeperingsmetode (Incremental Sum of Squares) gegroepeer. Vier bio-areas, nl. ‘n Noordelike-, Suidelike-, Sentrale en Westelike bio-area is identifiseer. Klassifikasieboom metodologie (Classification and Regression Trees, CART) asook Kanoniese Annalises (Cannonical Correspondence Annalysis, CCA) is gebruik om hierdie geografiese areas in terme van ‘n aantal omgewingsveranderlikes te karakteriseer. Vier spesieversamelings, twee groter en twee kleiner versamelings, is in ooreenstemming met hierdie vier areas geïdentifiseer. Die Noordelike en Suidelike spesieversamelings is die groteres en kan beskryf word as die faunas van onderskeidelik ‘n ariede en gematigde sone. Die kleiner Sentrale versameling bestaan hoofsaaklik uit rots-lewende spesies en mag die evolusionêre oorblyfsels verteenwoordig van ariede en gematigde faunas waarvan die verspreidings herhaaldelik as gevolg van klimaatsveranderingsiklusse uitgebrei en gekrimp het. Die Weskus versameling is ook ‘n kleiner een en kan as ‘n sub-versameling van die Noordelike een beskou word, maar spesifiek tot die kus klimaat aangepas. Die klassifikasie van hierdie bio-areas word ondersteun deur die analiese van die omgewingsveranderlikes. Die feit dat vier kenmerkende versamelings reptiele, elk met sy besondere omgewingsvereistes, in hierdie relatief klein geografiese area ontmoet, dui daarop dat die suid-westelike deel van Suid-Afrika biogeografies kompleks is. Die GCBK inkorporeer die grootliks ooreenstemmende sentrums van endemisme en rykheid wat langs die Weskus en in die groter Cederberg area voorkom. Alhoewel die sentrum van melanistiese endemiese spesies, in die Saldanha-Langebaan omgewing, net buite die grense van die Korridor val, voldoen die GCBK grootliks aan die vereistes vir die effektiewe bewaring van reptiele in die gebied. Die voorsiening van noord-suid verspreidingsweë langs die Kaapse Plooiberge binne die Korridor word beskou as voldoende om die gevolge van klimaatsverandering te buffer. Daarinteen is daar kommer oor die vermoeë van die GCKB om ‘n doeltreffende bydrae te maak tot die voortbestaan van die spesieversameling wat met die nou kussone langs die Weskus geassosieer is.
Cotterill, Fenton P. D. "The evolutionary history and taxonomy of the Kobus leche species complex of South-Central Africa in the context of palaeo-drainage dynamics." Thesis, Stellenbosch : Stellenbosch University, 2006. http://hdl.handle.net/10019.1/21773.
Full textENGLISH ABSTRACT: This multi-disciplinary study compiled taxonomic and biogeographical data to elucidate the extant diversity of lechwe antelopes (Kobus leche complex), and reconstruct their evolutionary history. Their diversification has been confined to wetlands across the south-central Africa plateaux. Lechwes are specialist grazers in water meadow floodplains; these stenotopic habitat requirements are invoked to explain why their evolution is atypical of terrestrial large mammals. Combined analyses of morphological (171 adult males), genetic (208 genotyped individuals) and palaeo-environmental datasets, revealed a recent (Middle Pleistocene) pulse of speciation in the K. leche complex. Multivariate morphometric analyses revealed the presence of five distinct groups that could be tied to the geography of the region. Furthermore, the genetic analyses supported the existence of at least four of these lineages, which show significant population separation at the level of the mtDNA control region. Most of the differences among populations were confined to frequency differences among populations and Bayesian analyses strongly suggest that the pattern obtained is the result of the retention of ancestral haplotypes with limited female geneflow among the extant populations. Evolution of the five lineages identified by the morphological and population genetic analyses were further investigated by making use of additional genetic data (mtDNA cyt b, SPTNB, SRY, Protamine 1, and b-Fibrinogen) and a subset of the samples. Topologies were largely unresolved due to the recent common ancestry of the lineages. Following the Evolutionary Species Concept, which was motivated by a philosophical review, five allopatric species could be recognized (anselli, kafuensis, leche, robertsi and smithemani). A model of drainage evolution compiled disparate facets of biological and geological evidence to detail interlinked histories of wetlands and their biota across the south-central Africa plateaux. This wetland archipelago is recognized as a distinct biogeographical unit in its own right - the Katanga-Chambeshi region. Evolutionary diversification of lechwes represents a dominant biogeographical signal reflecting how the aquatic biota have evolved in tandem with palaeo-drainage dynamics across this evolutionary theatre. Delimitation of key events in lechwe and drainage evolution was refined by archaeological dating of the Victoria Falls Formation, to decipher when the Zambezi river eroded the Batoka gorge. Demographic expansion in K. leche s.s (early Middle Pleistocene) corresponds to dessication of Palaeo-Lake Makakgadikgadi while more recent phylogeographic signals correspond to the tenure of Palaeo-Lake Bulozi. These speciation events in the Middle Pleistocene preceded peripatric speciation of K. kafuensis that accompanied the morphosis of the Kafue Flats (from palaeo-lake to floodplain), when the Kafue River attained its modern topology. The present study highlights that Lechwes represent a biota of evolutionary vibrant clades, rich in endemic species. As ecologically-dominant species in wetlands, lechwes deserve priority conservation attention, which is challenged to perpetuate evolutionary and ecological processes across an archipelago straddling five countries.
AFRIKAANSE OPSOMMING: Die multidisiplinêre studie bring saam taksonomiese en biogeografiese data om die evolusionêre geskiedenis en huidige diversitiet van basterwaterbokke (Kobus leche kompleks) te verklaar. Hulle diversifikasie is beperk to vleilande regoor die suid-sentraal Afrika plato. Basterwaterbokke is gespesialiseerde grasvreters in grasvloedvlaktes; hierdie stenotipiese habitatsvereiste word voorgehou om te verduidelik hoekom die evolusie van hierdie diere atipies is vir terrestriële groot soogdiere. Gekombineerde analise van morfologie (171 volwasse manlike diere), geneties (208 genotipes) en plaeo-omgewings datstelle toon aan dat daar ‘n onlangse (middel Pleistoseen) pols van spesiasie plaasgevind het in die K. lechwe kompleks. Multivariate morfometriese analyses het aangetoon dat vyf verskillende groepe diere bestaan wat ook sin gemaak het op grond van geografiese ligging. Verdermeer, die genetiese analise het die bestaan van ten minste vier van hierdie lyne geondersteun wat betekenisvolle bevolkings isolasie vertoon het op die vlak van die mtDNA kontrole gebied. Meeste van die verskille tussen bevolkings was beperk to frekwensieverkille tussen die bevolkings en Bayesian analise het sterk aanduidings getoon dat die patroon wat gekry is die gevolg was van die behoud van voorvaderlike haplotiepes met beperkte vroulike geenvloei tussen die huidige bevolkings. Evolusie van die vyf lyne wat deur die morfologie en bevolkingsgenetika studies geidentifiseer is was verder ondersoek deur gebruik te maak van addisionele genetiese data (mtDNA cytb, SPTBN, SRY, Protamien 1, en b-Fibrinogeen) en ‘n subset van die monsters. Topologieë was hoofsaaklik onopgelos as gevolg van die kort tyd tot die onlangse gemeenskaplike voorouer van lyne. Deur die Evolusionêre Spesies Konsep aan te hang, wat gemotiveer is deur ‘n filosofiese oorsig, is vyf allopatriese spesies herken (anselli, kafuensis, leche, robertsi and smithemani). ‘n Model wat dreinerings evolusie voorstel het verskeie fasette van biologiese en geologiese bewyse saamgvat om die verbindingsgeskiedenis van vleilande en hulle biota oor die suidsentraal Afrika plato te beskryf. Die vleiland argipelago word herken as ‘n onafhanklike biogeografiese eenheid in sy eie reg – die Katanga-Chambeshi streek. Evolusionêre diversifikasie van basterwaterbokke verteenwoordig ‘n dominante biogeografiese sein wat voortsel hoe die akwatiese biota ontwikkel het in tandem met die palaeo-dreinerings dinamika in hierdie evolusionêre konsert. Die afbakening van sleutelgebeure in basterwaterbok en dreinerigsevolusie is beter toegelig deur argeologiese datering wat gebasseer was op die vorming van die Victoria Valle om te bepaal waneer die Zambezi rivier die Batoka skeurgroef gevorm het. Demografiese uitbreiding binne K. leche s.s (gedurende die vroë Middel Pleistoseen) stem ooreen met die uitdroging van Palaeo-Meer Makakgadikgadi terwyl meer onlangse filogeografiese syne ooreenstem met die ontstaan van Palaeo-Meer Bulozi. Hierdie spesiasie gebeure in die Middel Pleistoseen het die peripatriese spesiasie van K. kafuensis voorafgegaan wat die morfose van die Kafue Vlaktes vergesel het (van palaeo-meer na vloedvlakte), toe die Kafue Rivier sy huidige vorm aangeneem het. Die huidige studie het uitgelig dat basterwaterbokke verteenwoordig ‘n biota van evolusionêre energieke eenhede, ryk aan endemiese spesies. As ‘n ekologiese dominante spesie in vleilande, moet basterwaterbokke as ‘n prioriteit gesien word in bewaring, waar dit dan die geleentheid sal hê om voort te bou op die evolusionêre en ekologiese prossese van die archipelago wat oor vyf lande strek.
Melly, Brigitte Leigh. "The zoogeography of the cetaceans in Algoa Bay." Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1005534.
Full textDiedericks, Genevieve. "Phylogeography of the Cape girdled lizard, Cordylus cordylus : investigating biogeographic patterning in the Cape floristic region (CFR)." Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85866.
Full textENGLISH ABSTRACT: In the present study I examined the phylogeography of the rupicolous Cape girdled lizard, Cordylus cordylus. Samples were collected across the species distribution range from 63 localities in the Eastern and Western Cape and Free State provinces of South Africa, yielding a total sample size of 207 specimens. Four DNA loci, two nuclear (PRLR, PTPN12) and two mitochondrial (16S rRNA, ND2), were sequenced. Bayesian inference, maximum likelihood and maximum parsimony methods were employed to test evolutionary relationships among populations, followed by population structure analyses, divergence time estimations and niche modelling. My results confirm the species monophyly and revealed the presence of two distinct clades. Clade 1 comprised specimens from the western and southern portions of the Western Cape coast, while clade 2 comprised specimens from the southern and eastern Cape coast and adjacent interior of the Eastern and Western Cape and Free State provinces. An area of sympatry between the two clades was observed in the Breede river valley. The divergence time estimates revealed an Early Pliocene (4.31 Ma), Late Miocene (6.01 Ma) divergence for each of the two clades retrieved. Phylogeographic data suggest that clade 1 is younger (lower haplotypic and nucleotide diversity), in comparison to clade 2. Furthermore, the niche modelling shows that C. cordylus occupies a wide range of unfavourable habitats. The absence of marked phylogeographic patterning within clades is very uncharacteristic for a rupicolous vertebrate species. The ecological pliability and generalist nature of C. cordylus presumably contributed to the observed phylogeographic pattern and have facilitated the absence of within clade differentiation. Moreover, I suggest that microclimatic variables, rather than geographic barriers influence the genetic structuring of C. cordylus.
Smit, Hanneline Adri. "Phylogeography of three Southern African endemic elephant-shrews and a supermatrix approach to the Macroscelidea." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/21442.
Full textENGLISH ABSTRACT: The order Macroscelidea has a strict African distribution and consists of two extant subfamilies, Rhynchocyoninae with a single genus that includes three species, and the Macroscelidinae represented by the remaining three genera, Elephantulus that includes 10 species, and the monotypic Macroscelides and Petrodromus. On the basis of molecular, cytogenetic and morphological evidence, Elephantulus edwardii (Cape rock elephant-shrew), the only strictly South African endemic species, was shown to comprise two closely related taxa. A new Elephantulus taxon, described here is reported for the first time. It has a restricted distribution in the central Nama Karoo of South Africa. Apart from important genetic distinctions, Elephantulus sp. nov. has several relatively subtle morphological characters that separate it from E. edwardii. Molecular sequences from the mitochondrial cytochrome b gene and the control region of E. edwardii sensu stricto suggests the presence of a northern Namaqua and central Fynbos clade with four evolutionary lineages identified within the latter. The geographic delimitation of the northern and central clades corresponds closely with patterns reported for other rock dwelling vertebrate species indicating a shared biogeographic history for saxicolous taxa in South Africa. Elephantulus rupestris (western rock elephant-shrew) and Macroscelides proboscideus (round-eared elephant-shrew) are two taxa with largely overlapping distributions that span the semi-arid regions of South Africa and Namibia. Based on mitochondrial DNA sequence data E. rupestris has a structured genetic profile associated with a habitat of rocky outcrops compared to M. proboscideus that inhabits gravel plains, where the pattern is one of isolationby– distance. Chromosomal changes, apart from heterochromatic differences, are limited to variation in diploid number among elephant-shrew species. These range from 2n=26 (E. edwardii; E. rupestris; Elephantulus sp. nov.; E. intufi; E. brachyrhynchus and M. proboscideus) to 2n=28 in both Petrodromus tetradactylus and E. rozeti to 2n=30 in E. myurus. Cross-species chromosome painting (Zoo-Fluorescence in situ hybridization or zoo-FISH) of E. edwardii flow-sorted probes that correspond to the five smaller sized autosomes (8-12) and the X chromosome showed no evidence of synteny disruption among Elephantulus sp. nov., E. intufi, E. myurus, P. tetradactylus and M. proboscideus, and reinforced the G-banding observations underscoring the conservative karyotypes in these species. A comprehensive phylogeny including all described elephant-shrew species is presented for the first time. A multigene supermatrix that included 3905 bp from three mitochondrial (12S rRNA, valine tRNA, 16S rRNA) and two nuclear segments (Von Willebrand factor [vWF] and exon 1 of the interphotoreceptor retinoid binding protein [IRBP]) was analysed. Cytogenetic characters, previously described morphological, anatomical and dental features as well as allozyme data and penis morphology were evaluated and mapped to the molecular topology. The molecular findings did not support a monophyletic origin for the genus Elephantulus and suggests that both the monotypic Petrodromus and Macroscelides should be included in Elephantulus. Molecular dating suggests that an arid-adapted Macroscelidinae lineage dispersed from east Africa at ~11.5 million years ago via the African arid corridor to southwestern Africa. Subsequent speciation events within the Macroscelidinae are coincidental with three major periods of aridification of the African continent.
AFRIKAANSE OPSOMMING: Die orde Macroscelidea het ’n verspreiding beperk tot Afrika en sluit twee bestaande subfamilies in, die Rhynchocyoninae wat drie spesies binne ’n enkele genus insluit en die Macroscelidinae verteenwoordig deur drie genera, Elephantulus (10 spesies) en die monotipiese Macroscelides en Petrodromus. Gebaseer op molekulêre, sitogenetiese en morfologiese bewyse, bestaan E. edwardii, tot op datum die enigste streng endemiese Suid- Afrikaanse klaasneusspesie, uit twee nabyverwante taksa. Die nuwe Elephantulus takson, hierin beskryf, het ’n beperkte verspreiding in die sentraal Nama Karoo van Suid-Afrika. Afgesien van belangrike genetiese bewyse wat die beskrywing van die nuwe spesie ondersteun, word Elephantulus sp. nov. gekenmerk deur ’n aantal subtiele morfologiese karakters wat dit onderskei van E. edwardii. Binne E. edwardii sensu stricto, het mitochondriale molekulêre volgordes beduidende substruktuur aangedui regoor die spesies se verspreiding. Die data het die teenwoordigheid van ’n noordelike Namakwa en sentrale Fynbos klade aangetoon met vier evolusionêre lyne binne die laasgenoemde. Die geografiese skeiding van die noordelike en sentrale klades stem grootliks ooreen met patrone in ander rotsbewonende vertebraat spesies, wat op ’n gedeelde biogeografiese verlede in Suid-Afrika dui. Elephantulus rupestris (westelike klipklaasneus) en Macroscelides proboscideus (ronde-oor klaasneus) is twee taksa met verspreidings wat grootliks oorvleuel in die semi-woestyn streke van Suid-Afrika en Namibië. Mitochondriale DNS volgorde-bepaling dui op ’n gestruktueerde genetiese profiel binne E. rupestris, geassosieer met ’n habitat van rotskoppies, in vergelyking met ’n isolasie-deur-afstand patroon wat M. proboscideus, wat op gruisvlaktes aangetref word, karakteriseer. Chromosoom verandering, afgesien van heterochromatiese verskille, is beperk tot ’n strukturele verandering van ‘n diploïede getal van 26 (E. edwardii; E. rupestris; Elephantulus sp. nov.; E. intufi; E. brachyrhynchus en M. proboscideus) tot 2n=28 in beide Petrodromus tetradactylus asook E. rozeti en 2n=30 in E. myurus. Kruis-spesies chromosoom fluoressent hibridisasie (“zoo-FISH”) van die vloei-sorteerde merkers toegewys tot die vyf kleiner grootte outosome (8-12) asook die X chromosoom van E. edwardii tot metafase chromosome van Elephantulus sp. nov., E. intufi, E. myurus, P. tetradactylus en M. proboscideus het geen bewyse getoon van sintenie-verbreking nie en versterk G-bandbepaling waarnemings wat die konserwatiewe kariotipes in hierdie spesies ondersteun. ‘n Volledige evolusionêre filogenie, verteenwoordigend van alle erkende klaasneusspesies, word vir die eerste keer voorgestel. As sulks is ’n multigeen supermatriks wat gebaseer is op 3905 bp van drie mitochondriale (12S rRNA, valien tRNA, 16S rRNA) en twee nukluêre segmente (Von Willebrand faktor [vWF] en ekson 1 van die interfotoreseptor-retinoïed-bindende proteïen [IRBP]) ingesluit. As toevoeging, is nuwe sitogenetiese data, voorheen beskryfde morfologiese, anatomiese en dentale karakters sowel as data van allosieme-analises en penis morfologie ge-evalueer en nie-molekulêre ondersteuning aangedui op die molekulêre topologie. Die molekulêre bevindinge ondersteun nie ’n monofiletiese oorsprong vir Elephantulus nie en stel voor dat beide die monotipiese Petrodromus en Macroscelides ingesluit moet word in die genus Elephantulus. Molekulêre datering stel voor dat ’n dor-aangepasde Macroscelidinae lyn versprei het vanaf oos Afrika ~11.5 miljoen jaar gelede deur die “droeë Afrika korridor” tot in suidwestelike Afrika. Verdere spesiasie gebeurtenisse binne die Macroscelidinae kan nouliks geassosieer word met drie groot periodes van verdorring in Afrika.
Van, Niekerk Mark Harry. "Quantifying crop damage by Grey crowned crane balearica regulorum regulorum and evaluating changes in crane distribution in the North Eastern Cape, South Africa." Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1005436.
Full textDowney, Nicola Jean. "The role of the deep spawning grounds in chokka squid (Loligo reynaudi d'orbigny, 1845) recruitment." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1011867.
Full textMidgley, John Claude. "Invasive perennial species in an agricultural area of the Western Cape Province : distribution and relationship with various land-use types." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/20899.
Full textENGLISH ABSTRACT: This project consists of two botanical investigations in an agricultural area of the Western Cape Province. A farm known as De Rust, in the Elgin Valley, was used to sample the geographic location, density, height and life stage of six prominent invasive plant species in various land-use categories. In the first investigation, the density, height and age structures of the six invasive species populations were analyzed. The density distribution of the six species was also displayed cartographically. Species were then ranked according to the potential threat that they pose to the conservation of the remaining natural areas on the farm. Results indicated that Acacia mearnsii and Acacia saligna are the major invaders at De Rust and that Hakea sericea can be considered as an emerging invader. The second investigation explores the statistical relationship between the various land-use categories and density, height and age of the six prominent invaders identified in the first investigation. The loglikelihood ratio analysis of observed frequencies resulted in statistically significant (P<0.01; P-values range between 1.35 x 10-3 and 2.7 x 10-224) relationships between certain land-use types and certain invasive species. A conclusion was reached that it could be useful to include land-use categories in simulation models of invasive plant species distribution and spread.
AFRIKAANSE OPSOMMING: Hierdie projek behels twee botaniese ondersoeke in ‘n landbou gebied van die Weskaap. Die plaas bekend as De Rust, in die Elgin Vallei, was gebruik vir die versameling van data te doen met die geografiese ligging, plant digtheid, lengte en lewens stadium van ses prominente indringer plant spesies in verskeie landgebruik kategorieë. Die digtheid, lengte en ouderdomstruktuur van ses indringerspesies was in die eerste ondersoek geanaliseer. Die verspreiding van digtheid was ook in kaarte uitgelê. Spesies was daarna volgens hulle potentiële dreiging teen die bewaring van oorblywende natuurlike dele van die plaas in ‘n rangorde geplaas. Resiltate dui aan dat Acacia mearnsii en Acacia saligna die belangrikste indringer plante op De Rust is en dat Hakea sericea as ‘n opkomende indringer beskou kan word. Die tweede ondersoek kyk na die verhouding tussen verskeie grondgebruik kategorië en die digtheid, lengte en ouderdom van die ses prominente indringer spesies wat in die eerste ondersoek identifiseër is. ‘n Log tipe ratios ontleding van bewaarde frekwensies het ‘n statisties belangrike uitkoms gehad (P<0.01; P-waardes tussen 1.35 x 10-3 en 2.7 x 10-224) vir die verhoudings tussen sekere grondgebruik tipes en sekere indringer spesies. Die gevolgtrekking was dat dit handig mag wees om grondgebruik kategorieë in simulasies van indringer plant verspreiding te gebruik.
Mataruse, Gamuchirai. "Phylogeography and conservation of a newly identified galaxiid from the Joubertina area, South Africa." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1003050.
Full textGilbert, Matthew Edmund. "The zonation of coastal dune plants in relation to sand burial, resource availability and physiological adaptation." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1003764.
Full textEdwards, Shelley. "Phylogeographic variation of the Karoo bush rat, Otomys unisulcatus : a molecular and morphological perspective." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2108.
Full textPhylogeographic genetic structure has been documented for a number of southern African terrestrial taxa. Information regarding geographic population genetic structuring in multiple taxa, with differing life histories, can provide insights into abiotic processes such as vicariance. A fragment of the cytochrome b mitochondrial DNA gene of a plains-dwelling species, Otomys unisulcatus, was sequenced and analysed. Two closely related geographic assemblages were found. The first assemblage (lowland group) contains populations from both the eastern and western parts of the species range, and the second comprises populations from the Little Karoo (central group). The lowland group was shown to be in a state of population expansion after a relatively recent mitochondrial DNA (mtDNA) coalescence, while the genetic signature of the central assemblage was characterized by more genetic diversity indicative of an older lineage/genetic refuge. Areas of higher elevation (namely mountain ranges) appeared to be the main factor limiting gene flow between these two groups. Aridification cycles due to glacial maximum periods probably resulted in increased dispersal leading to the widespread distribution of common haplotypes throughout the lowland group. Morphological variation in skull shape and size has been shown to follow environmental clines in some rodents. Geometric morphometric analyses on the ventral and dorsal views of the craniums of O. unisulcatus were utilised to test whether the population groupings obtained in the genetic analyses would be recovered by morphometric analyses. In addition, it was also investigated which of the environmental factors investigated influenced skull shape and size. The genetic groupings were not recovered for either the cranial shape or size. Size variation in the females correlated positively with annual rainfall, and so by proxy with habitat productivity, indicating that females which inhabited areas with lower rainfall would be larger. The significant relationship between females’ centroid sizes and rainfall was thought to be as a result of the increased nutrient requirement by this gender in the production of offspring. The males did not show a significant correlation between any of the environmental variables and centroid size. There was a significant difference between the skull shapes of the genders, further verifying the sexual dimorphism in the species. Three major clusters were found (according to cranium shape) using a Two-Block Partial Least Squares Analysis (2B-PLS), which relate to the biome boundaries within the species’ range. Variations in shape were attributed to the varying needs for strong masticatory muscles resulting from differing diets. The skull shapes of specimens occurring along the escarpment were intermediate between the first two clusters. Cranial shape in the male dorsal view dataset was significantly correlated with the environmental variables block, possibly due to the much lower minimum temperature in the Sutherland population (a population which was not included in the female analyses). It was concluded that differing diets of individuals in the respective biomes influenced the shape of the cranium of both genders. The sexual dimorphism in the cranium shapes may be as a result of the females digging tunnels (using their teeth) underneath the stick nests. Otomys unisulcatus show high levels of phenotypic plasticity throughout the range and it thus appears that the species can adapt fast to the different environmental variables.
Luyt, Eustatius du Chavoux. "Models of Bontebok (Damaliscus pygargus pygargus, Pallas 1766) habitat preferences in the Bontebok National Park and sustainable stocking rates." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/21218.
Full textENGLISH ABSTRACT:This study concentrates on the Bontebok (Damaliscus pygargus pygargus Pallas 1766) population of the Bontebok National Park. Using a combination of literature research, field observations, satellite imagery, Geographic Information System mapping and dung analysis, their habitat preferences within the Park are ascertained and compared to different behavioural and environmental factors. Considering vegetation composition and height, grass cover, burning history, general topography, water availability, actual diet quality (from faecal analysis) and population distribution, the best predictor of spatial pattern are investigated with GIS Dempster-Shafer models. The historical density distribution of the animals in the Park can be used to predict sustainable stocking rates. As far as possible, the results for the Bontebok are compared to those of the other larger herbivores in Bontebok National Park i.e. Red Hartebeest, Cape Mountain Zebra and Grey Rhebuck. These results should be useful for Wildlife Managers to know how to manage veld for Bontebok and at what stocking rates this can be done sustainably.
AFRIKAANSE OPSOMMING: Hierdie studie fokus op die Bontebok (Damaliscus pygargus pygargus, Pallas 1766) bevolking van die Bontebok Nasionale Park. Deur ‘n kombinasie van literatuurstudie, veldobservasies, satlietbeelde, Geografiese Inligtingstelsel (GIS) kartering en mis-analise te gebruik, word Bontebok habitatvoorkeure in die Park vasgestel en met verskillende gedrags- en omgewingsfaktore vergelyk. Deur te kyk na plantegroei-samestelling en hoogte, grasbedekking, brandgeskiedenis, algemene topografie, water-beskikbaarheid, diëet kwaliteit en die Bontebokke se waargenome ruimtelike verspreiding, word die faktor wat die verspreidingspatroon die beste voorspel, m.b.v. GIS Dempster-Shafer modelle ondersoek. Die historiese digtheidsverspreiding van diere in die Park word gebruik om volhoubare veldladings te voorspel. Sover moontlik word die resultate vir Bontebok vergelyk.met die ander groter herbivore in die Bontebok Nasionale Park, te wete Rooi Hartebees, Kaapse Bergsebra en Vaalribbok. Hierdie resultate behoort vir Natuurlewe-bestuurders tot nut te wees as riglyne vir veldbestuur en volhoubare veldladings van Bontebok.
Pasternak, Graham M. "Environmental effects on group structure and vigilance in vervet monkeys." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Psychology, c2011, 2011. http://hdl.handle.net/10133/3147.
Full textxiii, 79 leaves : ill., maps ; 29 cm
Rivers-Moore, Nicholas Andrew. "Water temperature and fish distribution in the Sabie River system : towards the development of an adaptive management tool." Thesis, 2003. http://hdl.handle.net/10413/3597.
Full textThesis (Ph.D.)-University of Natal, Pietermaritzburg, 2003.
Botts, Emily Anne. "Distribution change in South African frogs." Thesis, 2013. http://hdl.handle.net/10539/12368.
Full textPhama, Justin Onkemetse. "The population status of the threatened endemic plant Aloe peglerae in the Magaliesberg mountain range." Thesis, 2013. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000524.
Full textThe aim of this study was to determine the current population status of Aloe peglerae in the Magaliesberg Mountain Range.
Marokane, Cynthia Kwena. "Metabolomic analysis of Sclerocarya birrea (A. Rich) Hochst : to determine the differences in chemical profile and anti-diabetic properties in relation to geographical distribution." Diss., 2015. http://hdl.handle.net/10500/22560.
Full textAgriculture, Animal Health and Human Ecology
M. Sc. (Agriculture)
Oberholster, Tanzelle. "Characterisation of the genetic diversity of the southern cattle tick, Rhipicephalus microplus, populations from South Africa." Diss., 2014. http://hdl.handle.net/2263/43208.
Full textDissertation (MSc)--University of Pretoria, 2014.
lk2014
Genetics
MSc
Unrestricted
Adjorlolo, Clement. "Estimating woody vegetation cover in an African Savanna using remote sensing and geostatistics." Thesis, 2008. http://hdl.handle.net/10413/420.
Full textThesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
Hoveka, Lerato Nakedi. "Invasive alien plants of South Africa’s freshwater systems : accelerating identification of species and climatically suitable areas for species invasion." Thesis, 2014. http://hdl.handle.net/10210/11353.
Full textIn South Africa, controlling and eradicating Azolla filiculoides and Eichhornia crassipes cost annually approximately US$ 60 million to the national budget. However, the success of these operations is mixed because invasive aquatic plants often spread very rapidly either before they are spotted or before decisions are taken to implement control actions. This limitation is further exacerbated by difficulties in determining the invasion potential of newly introduced or unknown aquatic plants, as well as difficulties inherent to species identification. Resolving these drawbacks requires pre-emptive actions such as identifying areas that are most vulnerable to invasion by alien plants. In this study, I first explore whether molecular technique such as DNA barcoding can be useful to: i) overcome potential limitation of morphology-based identification of invasive aquatic plants; and ii) establish successful control of these invasives. For this purpose, I tested the utility of official DNA barcodes (rbcLa + matK or core barcodes), trnH-psbA, and the core barcode + trnH-psbA to identify invasive aquatic plants of South Africa’s freshwaters. Second, I use the technique of ecological niche modeling to identify most vulnerable freshwater systems to species invasion under current and climatic conditions. My analysis indicates that the core barcodes and matK regions perform poorer compared to trnH-psbA, which provides 100% successful identification alone or in combination with the core barcodes. This study therefore validates trnH-psbA as single best DNA barcode for invasive alien aquatic plants of freshwater systems in South Africa. Using this DNA region in BLAST analysis to screen plants species sold in aquarium market in Johannesburg, I found surprisingly that some prohibited species are already in circulation in the market. These include Hydrilla verticillata, egeria densa, Myriophyllum spicatum, and Echinodorus cordifolius. Furthermore, based on climatic parameters, I explored the distribution of the "bad five" aquatic species in South Africa, i.e. the most damaging invaders of freshwater systems. I found distinct distribution potentials for these species under current climatic conditions. Overall, 38% of all South Africa’s dams occur in areas climatically vulnerable to the invasion by the bad five with the Western Cape Province being the most vulnerable. However, under predicted climate change scenario, I found evidence for contrasting shifts in species range: species such as Azolla filiculoides, Eichhornia crassipes, Salvinia molesta might increase their range by at most 2% whilst the ranges of Myriophyllum aquaticum and Pistia stratiotes might contract by at most 5%. This range contraction and expansion will result in some dams currently vulnerable to invasion becoming resilient whilst others that are currently resilient might become vulnerable owing to climate change. This result demonstrates not only the utility of DNA barcoding in implementing control measures, but also provides ways of prioritising control/management efforts.
Ezike-Dennis, Uchechukwu Nneka. "The spatial distribution of HIV and AIDS in Gauteng, South Africa." Diss., 2007. http://hdl.handle.net/10500/1594.
Full textGeography
M.Sc. (Geography)
Chamane, Sindiso C. "Effect of fire frequency on herbivore distribution and behaviour in the Kruger National Park, South Africa." Thesis, 2012. http://hdl.handle.net/10413/10000.
Full textThesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
King, Helen. "Thermal physiology and predicted distribution of Zygogramma bicolorata (Chrysomelidae), a promising agent for the biological control of the invasive weed Parthenium hysterophorus in South Africa." Thesis, 2008. http://hdl.handle.net/10413/10737.
Full textThesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
McInnes, Alistair McIntyre. "Biology of the Grey-headed gull Larus cirrocephalus in South Africa." Thesis, 2006. http://hdl.handle.net/10413/10075.
Full textThesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
Niemand, Pieter Du Toit. "Analysing the spatial persistence of population and wealth during Apartheid / Pieter Du Toit Niemand." Thesis, 2015. http://hdl.handle.net/10394/15477.
Full textMCom (Economics), North-West University, Potchefstroom Campus, 2015
HAASOVÁ, Ivana. "Tasemnice čeledi Gryporhynchidae z Afriky." Master's thesis, 2009. http://www.nusl.cz/ntk/nusl-51551.
Full text