Morphometric and molecular analysis of variation in the southern African hedgehog, Atelerix frontalis (Eulipotyphla : Erinaceidae)

Abstract

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.