Freshwater fishes inhabiting Lakes are well known and popular model systems in evolutionary biology. Under geographically confined circumstances they are used to evaluate under which conditions and forces population differentiation could begin, speciation processes could take place and therefore genesis of biodiversity could start.

In my dissertation I try to understand processes of divergence using the example of a compact species flock of tropical freshwater fishes. Sailfin silversides (Teleostei: Atheriniformes: Telmatherinidae) are endemic to the island of Sulawesi and closely related to the well known rainbow fishes of Australia and New Guinea. Those fishes developed a comparatively small, but highly interesting radiation in the highland of Sulawesi. Besides different morphs concerning jaw morphology and body shape, there are spectacular male colour morphs, which are present under obvious sympatric conditions exhibiting distinct blue-whitish and yellow nuptial coloration.

The Malili Lakes consist of two small and three large lakes, the largest of which can be compared in size with approx. 561 km² to Lake Konstanz. Besides sailfin silversides, the lakes inhabit radiations of different gobies, ricefish, halfbeaks, freshwater gastropods and mussels, crabs, shrimps and sponges.

In close cooperation with the project supervisor Ulrich Schliewen, I use Amplified Fragment Length Polymorphisms (AFLPs) to examine population genetic patterns of the whole species flock and of a selected focus group. Data from ecological and sexual factors derived from diving transects and mating observations are used to contribute to understand mechanisms of differentiation. Using an experimental approach on mating preferences in the Lab, we try to understand female preferences under standardized conditions.

Our collection of telmatherinids fishes is the base for several additional examinations. Using Morphometric methods, we analyze body shape. Gut content analysis supplies complementary data to trophic ecology.

Asian freshwater fishes

Continuing the topic of my Diploma Thesis, I am interested in factors regulating diversity of tropical stream fish communities, in the zoogeography of Southeast Asia and in faunistic, taxonomic and systematic questions concerning different groups of fishes from that region.

Defensive morphology