The near-threatened southern African hedgehog, Atelerix frontalis (A. Smith, 1831) is divided into two subspecies based on its disjunct distribution of two allopatric populations. This is despite reservations because its nature and extent of geographic variation remains virtually unknown. The present study, therefore, represents the first analysis of geographic variation within A. frontalis and is based on a multidisciplinary approach involving traditional and two-dimensional geometric morphometric analysis of the cranium and mandible, and molecular data in order to test the validity of the subspecies designations. The results of all univariate and multivariate analyses of both traditional and geometric morphometric data were congruent and provide evidence for a north-westerly–south-easterly clinal pattern of variation with cranial configuration being positively correlated with both latitude and longitude. These results are supported by Neighbour-joining, Maximum Likelihood, and Maximum Parsimony analyses of Cyt-b and ND2 data that revealed no variation across a 377 bp and 1034 bp region sequenced for each gene, respectively, while a 377 bp control region sequenced revealed low levels of variation between representatives of the two recognized subspecies (0.54 % pairwise sequence divergence). These results together with the lack of pronounced steps in the clinal pattern of variation suggest that the recognition of subspecies within A. frontalis may be untenable such that its disjunct distribution may represent a recent divergence event. If this is the case, then the results in this study may have implications in the conservation management strategies for A. frontalis, since it could be argued that one disjunct population could act as a source population for the other. However, it is recommended that prior to the implementation of conservation management plans for the species, further studies involving a wide range of alternative systematic techniques need to be undertaken first in order to gain a better understanding of the nature and extent of geographic variation within A. frontalis. These suggested studies should focus on comprehensive sampling and analyses involving a range of environmental and/or climatic variables in an attempt to identify factors that may explain the disjunct distribution and the clinal pattern of variation within the southern African hedgehog. / Dissertation (MS)--University of Pretoria, 2011. / Zoology and Entomology / unrestricted

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Crustaceans of the genus Aegla occur in continental waters, in southern South America. The genus is composed by more than 70 species, most of them characterized by having restricted distributions. Unlike this pattern, the species Aegla longirostri and Aegla platensis have wide geographic distributions. Moreover, both species form non-monophyletic groups, which may indicate that these groups are formed by cryptic species. Therefore, the objective of this study was to analyze populations of A. longirostri and A. platensis through a geometric morphometric approach, in order to clarify their intraspecific relationships. For A. longirostri, we analyzed 120 individuals from 6 populations, totalizing 20 animals per population. For A. platensis, we analyzed 110 individuals from 11 populations (four Argentinean and seven Brazilian), totalizing 10 animals per population. For both species, the animals were photographed in dorsal view, and 19 landmarks were defined on the carapace. Both sides of the carapace were symmetrized, and the landmarks coordinates were superimposed. Variations in centroid size were tested with an analysis of variance (ANOVA) and Tukey s test. For A. longirostri, we also used a Procrustes ANOVA. Variations in carapace shape were explored through a principal component analysis (PCA), and afterwards through a linear discriminant analysis (LDA) and a canonical variate analysis (CVA), based on the first 8 principal components. The Mahalanobis distances between the populations were calculated. For statistical test of carapace shape differences, we used multivariate analysis of variance (MANOVA), and for pairwise comparisons among populations we used Bonferroni corrections for adjust of p-value after multiple MANOVAs. For A. longirostri, CV1 and CV2 represented 46.5% and 23.1% of the variation, respectively. The most geographically distant population showed the highest values of Mahalanobis distance. The pairwise comparisons showed that all populations of A. longirostri differ significantly in carapace shape. For A. platensis, CV1 and CV2 represented 28.5% and 22.2% of the variation, respectively. There was a separation between Argentinean and Brazilian populations, with high values of Mahalanobis distances between populations from both countries. The pairwise comparisons showed that all populations of A. platensis differ significantly in carapace shape, with the exception of a pair of Argentinean populations and a pair of Brazilian populations. Some characteristics of the aeglids indicate that these animals may have low dispersal potential, thus the geographic distance may have led to an interruption of the gene flow between populations. Added to the non-monophyletic grouping, the intraspecific difference in carapace shape in A. longirostri and A. platensis could be an evidence that populations of both species are fragmented. / Crustáceos do gênero Aegla ocorrem em águas continentais, no sul da América do Sul. O gênero é composto por mais de 70 espécies, caracterizadas em sua maioria por possuírem distribuições restritas. Ao contrário deste padrão, as espécies Aegla longirostri e Aegla platensis possuem distribuições geográficas amplas. Além disso, ambas as espécies formam agrupamentos não-monofiléticos, o que pode indicar que esses agrupamentos são formados por espécies crípticas. Portanto, o objetivo deste estudo foi analisar populações de A. longirostri e A. platensis através de técnicas de morfometria geométrica, visando esclarecer suas relações intraespecíficas. Para A. longirostri, foram analisados 120 indivíduos provenientes de seis populações, totalizando 20 animais de cada população. Para A. platensis, foram analisados 110 indivíduos provenientes de 11 populações (quatro argentinas e sete brasileiras), totalizando 10 animais de cada população. Para ambas as espécies, os animais foram fotografados em vista dorsal e foram selecionados 19 marcos anatômicos localizados na carapaça. Ambos os lados da carapaça foram simetrizados e as coordenadas dos marcos anatômicos foram sobrepostas. Variações no tamanho do centroide foram testadas através de análise de variância (ANOVA) de um critério e teste de Tukey. Para A. longirostri, também foi utilizada ANOVA de Procrustes. Variações na forma da carapaça foram exploradas através de análise de componentes principais (PCA), e posteriormente através de análise linear discriminante (LDA) e análise de variáveis canônicas (CVA), com base nos 8 primeiros componentes principais. Foi calculada a distância de Mahalanobis entre as populações. Variações na forma da carapaça foram testadas através de análise de variância multivariada (MANOVA) e MANOVAs par a par seguidas por correção de Bonferroni. Para A. longirostri, CV1 e CV2 corresponderam a 46,5% e 23,1% da variação, respectivamente. A população mais distante geograficamente apresentou os maiores valores de distância de Mahalanobis. As MANOVAs par a par demonstraram que todas as populações de A. longirostri diferem significativamente na forma da carapaça. Para A. platensis, CV1 e CV2 corresponderam a 28,5% e 22,2% da variação, respectivamente. Houve uma separação entre as populações argentinas e brasileiras, com valores de distância de Mahalanobis maiores entre as populações dos dois países. As MANOVAs par a par demonstraram que todas as populações de A. platensis diferem significativamente na forma da carapaça, com exceção de um par de populações argentinas e um par de populações brasileiras. Algumas características dos eglídeos indicam que esses animais possuem baixo potencial de dispersão, portanto, a distância geográfica pode ter levado à interrupção do fluxo gênico entre as populações. Somada à ausência de monofilia, a diferença intraespecífica na forma da carapaça em A. longirostri e A. platensis pode ser um indício de que populações de ambas as espécies estão fragmentadas.