The invasive guttural toad, Amietophrynus gutturalis

dc.contributor.advisorCouldridge, Vanessa
dc.contributor.advisorChanning, Alan
dc.contributor.authorTelford, Nicolas S.
dc.date.accessioned2016-04-05T13:56:16Z
dc.date.accessioned2024-10-30T11:28:06Z
dc.date.available2016-04-05T13:56:16Z
dc.date.available2024-10-30T11:28:06Z
dc.date.issued2015
dc.descriptionMagister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol)en_US
dc.description.abstractThe guttural toad, Amietophrynus gutturalis, Power 1927, is a common toad with a broad geographic range through much of temperate, sub-tropical and tropical southern and central Africa. Introduced to the islands of Mauritius and Reunion in the 1960’s, and subsequently to Cape Town in the 1990’s, the species has become invasive in its extra-limital ranges. Determining the invasion history of a species provides valuable information for conservation biologists and managers and it is fundamentally important for improving our understanding of the underlying processes of biological invasions. This study aimed to determine the source populations of the extra-limital populations from Mauritius and Cape Town. Furthermore, studies investigating genetic diversity and demographics of African Bufonidae are largely absent from the literature. Understanding the evolutionary history of the species may also assist with determining their invasive ability and identifying similar features in other bufonids such as Amietophrynus regularis and A. xeros. Using mtDNA sequence data from the 16S and ND2 markers four geographically distinct clades were identified through Bayesian phylogenies and haplotype networks. However, a spatial analysis of molecular variance (SAMOVA) indicated a grouping structure of three clades. A total of 16 haplotypes were identified from 53 samples for the 16S marker and 22 haplotypes were identified from 43 samples for the ND2 marker. Both the Mauritius and Cape Town invasive populations were found to have originated from the eastern clade. However, they matched the common haplotype from this region which was found across a vast area that spans the KwaZulu-Natal province and into the Mpumulanga and Limpopo provinces. This did not allow for identifying a more precise region for the origin of the founder populations. The presence of haplotypes unique to the Cape Town invasive population, which group with the eastern clade, indicates that there has potentially been more than one introduction event. Demographic analysis revealed a recent population expansion in both the northern (Fs = -2.92) and the eastern clades (Fs = -5.03). Significant genetic variation was found among groups (93.92%), with low variation among populations and among populations within groups. Population pairwise differences were found to be significantly different between all clades except between the central and the southern clade. There was a negligible difference in the genetic diversity of the invasive populations when compared to the eastern clade. The eastern clades’ genetic diversity was low compared to the two other clades and demographic analysis revealed that this region has undergone the most recent population expansion. The negligible difference between the eastern clades’ genetic diversity and both invasive populations indicate that founder effects and genetic bottlenecking should have no impact on the invasive populations.en_US
dc.description.sponsorshipNational Research Foundation (NRF)en_US
dc.identifier.urihttps://hdl.handle.net/10566/16726
dc.language.isoenen_US
dc.publisherUniversity of the Western Capeen_US
dc.rights.holderUniversity of the Western Capeen_US
dc.subjectAmietophrynus gutturalisen_US
dc.subjectPhylogeneticsen_US
dc.subjectPopulation geneticsen_US
dc.subjectConservation managementen_US
dc.subjectCape Townen_US
dc.titleThe invasive guttural toad, Amietophrynus gutturalisen_US

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