33 research outputs found

    Systematics of southern African Anostostomatidae (Orthoptera) based on morphological and molecular data

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    The eight southern African King Cricket genera, namely Bochus, Borborothis, Henicus, Libanasa, Libanasidus, Nasidius, Onosandridus, and Onosandrus are redescribed from type and museum material and a key to the genera is provided. Additionally, the status of Libanasidus impicta is investigated and species characteristics confirmed. A key to the two Libanasidus species is also provided. No morphological support for these eight southern African anostostomatid genera was attained with cladistic analysis, despite the incorporation of taxonomically important characters. High levels of homoplasy and possible incorrect species placement, resulting in character ambiguity within genera, renders many of the diagnostic characters of this group ineffective for resolving generic relationships. Genetic data based on the large ribosomal subunit (16S) did provide phylogenetic resolution between six of the genera with good bootstrap support. This confirmed speculation by previous authors as to the ancestral nature of Bochus and Borborothis to other genera within the Anostostomatini tribe, as well as the placement of Libanasa within a separate tribe, the Lutosini. The recent merge of the genus Platysiagon with Libanasa is also provisionally supported. Close association was obtained between Libanasidus and Nasidius with Onosandrus being more related to Bochus and Borborothis, supported by the lack of sexual dimorphism in Onosandrus and Borborothis. The phylogenetic position of the genera Henicus and Onosandridus remains unresolved. It is suggested that the designation of the eight anostostomatid genera in southern Africa are valid, but that species placement within these genera need to be revised to resolve character conflict. Focusing on the genetic and morphometric structuring within the famous Parktown Prawn, Libanasidus vittatus from southern Africa consistently suggests two main population assemblages. These correspond to a large North-South ranging population including individuals west of the prominent escarpment, and a smaller population including individuals from the eastern side of the escarpment. COI sequence data recovers two clades representing these two populations with good bootstrap support in likelihood, parsimony, Bayesian and distance analyses. Genetic divergence between the two clades averaged 3.3%, while population parameters estimated using maximum likelihood methods show low migration rates corresponding to less that one female migration per generation. A priori morphometric analyses including PCA&clustering methods show no biologically meaningful variation, suggesting that the two clades recovered represent cryptic sibling species. Inferring a molecular clock of 2% divergence per million years used for sister taxa, signifies isolation of the eastern population at 1.65 mya. A posteriori morphometric analyses confirmed the genetic results, based on 11 size-related measurements. This study provides a starting point for further work on the taxonomy, behaviour and ecology of these fascinating insects. Cytogenetics, multiple genetic loci and geometric morphometrics will provide useful insight into the taxonomic status of the 51 anostostomatid species in southern Africa and is promoted for further studies.Dissertation (MSc Entomology)--University of Pretoria, 2006.Zoology and Entomologyunrestricte

    Differentiation of two South African otter species (Aonyx capensis and Lutra maculicollis) from spraint based on partial CytB primer sets

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    AbstractAccurate species identification based on visual cues can be challenging due to morphological similarities and the cryptic nature of certain species. Thus a more conclusive method of identification is required, namely DNA barcoding. This is the case regarding two South African otter species, Cape Clawless otter (Aonyx capensis) and the spotted necked otter (Lutra maculicollis). Due to the cryptic nature of these animals faecal samples, known as spraints, are the easiest way of confirming the presence of the animal in an area. In this study, we compared results obtained for universal and partial CytB primer sets on collected spraint and tissue control samples. Universal CytB primers revealed a low percentage of amplified otter species from faecal samples (species specific amplification success of 10.9%) whereas, the partial CytB primer set resulted in successful amplification of 45 out of 55 (82%) samples. We were thus able to positively differentiate between the two otter species using the partial CytB primer set developed in this study. The ability to accurately identify species using partial DNA will be beneficial in understanding numerous aspects of the behaviour and ecological importance of animals in their environment

    A mathematical epidemiological model of gram-negative Bartonella bacteria : does differential ectoparasite load fully explain the differences in infection prevalence of Rattus rattus and Rattus norvegicus?

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    We postulate that the large difference in infection prevalence, 24% versus 5%, in R. norvegicus and R. rattus, respectively, between these two co-occurring host species may be due to differences in ectoparasite and potential vector infestation rates.Acompartmental model, representative of an infectious system containing these two Rattus species and two ectoparasite vectors, was constructed and the coefficients of the forces of infection determined mathematically. The maximum difference obtained by the model in the prevalence of Bartonella in the two Rattus species amounts to 4.6%, compared to the observed mean difference of 19%. Results suggest the observed higher Bartonella infection prevalence in Rattus norvegicus compared to Rattus rattus, cannot be explained solely by higher ectoparasite load. The model also highlights the need for more detailed biological research on Bartonella infections in Rattus and the importance of the flea vector in the spread of this disease.The National Research Foundation (NRF)http://www.tandfonline.com/toc/tjbd20ab201

    Molecular detection of yaba monkey tumor virus from a vervet monkey

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    Yaba monkey tumour virus (YMTV) was first diagnosed in a colony of captive rhesus monkeys (Macaca mulatta) in Yaba, Nigeria. It has been implicated as the cause of cutaneous nodules in wild baboons (Papio species), rhesus monkeys (Macaca mulatta) and cynomolgus monkeys (Macaca fascicularis). This article reports a case of cutaneous pox lesions caused by YMTV in a  free-ranging  adult  female  vervet  monkey  (Chlorocebus  pygerythrus)  from  the  Umkomaas coastal area in South Africa. The virus was identified by molecular sequencing from fragments of the insulin metalloprotease-like protein and intracellular mature virion membrane protein as well as the DNA polymerase genes. Phylogenetic analyses of these gene regions revealed a 99% similarity of the sample to YMTV. Although human disease caused by YMTV is normally mild,  it  is  recommended  that  persons  in  contact  with  non-human  primates  in  the  area  of Umkomaas who develop cutaneous lesions should inform their doctors of the possibility of this infection. The extent and significance of the virus to human and non-human primates in South Africa are not known. To the authors’ knowledge, this is the first diagnosis of YMTV in South Africa and in vervet monkeys

    Canine parvovirus detected from a serval (Leptailurus serval) in South Africa

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    Canine parvovirus first emerged in domestic dogs (Canis familiaris), most likely as a variant of the feline panleucopaenia virus. Relatively recently, canine parvovirus-2a and canine parvovirus-2b infections have been identified in both symptomatic and asymptomatic domestic cats, while canine parvovirus infections have also been demonstrated in wild felids. This report documents the first known case of canine parvovirus-2b detected in unvaccinated serval (Leptailurus serval) from South Africa. The serval presented with clinical signs of vomiting, anorexia and diarrhoea that responded to symptomatic treatment. Two weeks later, severe leucopaenia, thrombocytopenia and death occurred. Typical enteric histological lesions of parvovirus infection were not observed on histopathological examination of the small intestine; however, histological lesions consistent with septicaemia were present. Canine parvovirus was detected in formalin-fixed paraffin-embedded small intestine using polymerase chain reaction. Phylogenetic analysis of the sequence of the canine parvovirus viral capsid protein gene showed similarities between the sample from the serval and canine parvovirus-2b isolates from domestic dogs in Argentina and South Africa. A case of canine parvovirus-2b in a domestic dog from South Africa in 2012 that fell within the same clade as the serval sample appears distantly related because of the long branch length. The significance of these findings is explored. More extensive surveys of canine parvovirus in domestic and wild felids and canids are needed to understand the epidemiology of canine parvovirus in non-domestic felids in South Africa

    Evidence of a contact zone between two Rhabdomys dilectus (Rodentia : Muridae) mitotypes in Gauteng province, South Africa

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    Recent studies have described the presence of several mitochondrial lineages within Rhabdomys, which was previously considered to be a monotypic genus. The exact distributional limits of the species and subspecies and their contact zones are unclear. In this study we demonstrate that two monophyletic Rhabdomys dilectus mitochondrial lineages are present at two northern Gauteng province sampling sites in South Africa. Cytochrome b gene sequences, 896 nucleotides in length, generated for 36 Rhabdomys samples identified 10 unique haplotypes corresponding to eight R. dilectus dilectus haplotypes (from 32 individuals) and two R. d. chakae haplotypes (from four individuals). The present study provides the first empirical evidence for a contact zone for two R. dilectus conspecific mitochondrial lineages and contributes to the refinement of Rhabdomys distributional maps in southern Africa.South African National Research Foundationhttp://www.tandfonline.com/loi/tafz202016-03-31hb201
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