The Breede and associated river systems has small species of Pseudobarbus, Galaxias and Sandelia, with a large southern African tetraploid barb (currently in the genus Barbus) also occurring in the area. Some of the species are not currently recognised. We are investigating within and among population genetic variation at multiple sampling localities to assess the role that past climatic and geological changes have played on the evolutionary history of these species. We predict that the different genera will show a similar pattern of genetic differentiation among currently isolated river systems, despite several of them being connected only 18 000 years ago during the lower sea levels of the last glacial maximum. We expect that the pattern of genetic differentiation will be reflective of known geographic and climatic processes and we are also assessing whether genetic patterns are reflective of differences in habitat preference between the different species. Previous studies have shown that there is higher species diversity in the Cape Floristic Region than what is recognised by the current taxonomic classification. There will therefore be a need to revise the conservation status of the fish lineages of the study area.

Our research is funded by the National Research Foundation (South Africa), the International Foundation for Science (Sweden), the The Rufford Small Grants Foundation (UK) and WWF International (Global).

Previous publications:

Chakona A, Phiri C, Magadza CHD & Brendonck L (2008) The influence of habitat structure and flow permanence on macroinvertebrate assemblages in temporary rivers in northwestern Zimbabwe. Hydrobiologia, 607: 199-209.

Chakona A, Phiri C & Day JA (2009) Potential for Trichoptera communities as biological indicators of morphological degradation in riverine systems. Hydrobiologia, 621: 155-167.

Chakona A, Phiri C, Chinamaringa T & Muller N (2009) Changes in biota along a dry-land river in northwestern Zimbabwe: declines and improvements in river health related to land use. Aquatic Ecology. 10.1007/s10452-008-9222-7

Chakona A, Marshall B & Brendonck L (2007) The effect of fish predation on benthic macroinvertebrates in a seasonal stream in northwestern Zimbabwe. African Journal of Aquatic Science, 32: 251-257.

Chakona A & Marshall B (2008) A preliminary assessment of the impact of forest conversion from natural to pine plantation on macroinvertebrate communities in two mountain streams in Zimbabwe. African Journal of Aquatic Science, 33: 115-124.