Specifically, this includes taxonomy, systematics, phylogenetics, biogeography, phylogeography and population genetics of marine fishes (mostly tropical and subtropical, reef-associated taxa), and freshwater fishes and invertebrates (notably Crustacea).
Within these fields, I aim to address a number of fundamental issues. I routinely use genetic data to delineate species or test species boundaries, aiding taxonomy, in various taxa. My phylogenetic research addresses higher relationships within a number of taxa (e.g., cardinalfishes and snappers), to improve the existing taxonomy. These phylogenies are also applied to investigate the evolution of morphological, behavioural and physiological traits.
A thrust of my research investigates whether dispersal and vicariant biogeographic hypotheses explain patterns of species distribution and endemism, and contemporary spatial genetic diversity in the Western Indian Ocean and in southern African catchments. I am interested in how intraspecific phylogeographic structure, the distribution of genetic diversity and finer-scale patterns of gene flow intersect with higher biogeographic patterns in marine systems and freshwater environments; a key question being the influence of intrinsic life history features and extrinsic environmental features.
Recently, I have become interested in pursuing NGS and genomic approaches to look at the selective influence of features (such as environmental gradients) on genetic structure in non-neutral markers, with a view to understanding physiological adaptations and gene expression.
My population genetic work generally has a conservation or management focus, identifying fisheries stocks in the south-western Indian Ocean and along the South African coast or evolutionarily significant units in freshwater systems for conservation. My research has coupled population genetic studies and ecological approaches (traditional mark-recapture studies) to determine effective dispersal and gene flow in marine fish species.
Future research will investigate the invasion pathways of non-native taxa in freshwater.