Title of the project
Adaptive radiation in Lake Tanganyika
Management
Prof Dr Matthias Glaubrecht
Doctoral project: Wencke Krings (2015-2020)
Org. categorisation
Department of Animal Biodiversity
Description of the
Lake Tanganyika as a unique habitat
Lake Tanganyika is the largest and deepest rift valley lake in Africa. This long-term lake is seen as an evolutionary hotspot of speciation that provided stable environmental conditions for more than 10 million years: a unique opportunity for diversification and trophic specialisation.
Tropical specialisation by means of the radula appears to be an important key factor in adaptive radiation in snails. This organ for food intake and processing in gastropods shows an enormous morphological diversity.
The disparity of the radulae is regarded as a phylogenetic legacy on the one hand, but also as a response to environmental requirements on the other. However, the function of the organ in particular has so far only been studied in outline.
Snail teeth in the focus of research
The project uses the example of the Paludomidae family to apply current methods of analysing form, material and function in order to build on basic research into radiation and evolution. It is being investigated whether branches of a radiation can be regarded as a response to the availability of food and substrate niches.
Analyses of the radula teeth and their hardness and elasticity in cooperation with the Department of Functional Morphology and Biomechanics at Kiel University showed that not only the teeth but also their embedding or anchoring correlate with the ecological niche.
The teeth also fulfil different functions: Some detach the food from the substrate, others grind it together afterwards. These results are supported by mathematical feeding simulations.
What the shell size reveals about the snails
Another focus of the project is on annidation driven by shell size: The paludomid species of Lake Tanganyika stand out due to immense size differences between the adults.
This is a strong indication that the species avoid or reduce competition through differences in body size. The study is based on biometric data sets of thousands of animals, which are analysed and linked to the ecology of the animals.
PhD project: "Trophic specialisation of paludomid gastropods from 'ancient' Lake Tanganyika reflected by radular tooth morphologies and material properties", Wencke Krings (2020)
Impressions
