Sebastian Büsse, Stanislav N. Gorb
Odonata larvae are important predators in their biotopes that catch their prey with a unique and highly efficient catching apparatus, known as prehensile mask, which is formed by the modified labium. By means of this prehensile mask the odonatan larvae are able to capture potentially fast moving organisms up to their own size. Usually, the nymphs attack their prey, invertebrates as well as small vertebrates like fish or tadpoles, with their long, extensible labium from an ambush.
In the framework of this project, the morphology, mechanics and kinematics of the unique larval odonatan labial extension mechanism, the mouthparts interactions and the prey capturing process will be studied in different Odonata species. The high speed of the unfolding indicates that in addition to muscle action and hydraulics there should be locking mechanisms and/or resilin springs used for energy storage.
The basic morphology of the larval head of Odonata and the material composition with special emphasis on the distribution of resilin will be studied using various microscopic techniques like X-ray tomography, fluorescence microscopy and advanced scanning electron microscopy with cryofixation. This will help us to understand the functional principles behind these structures. Subsequently, the kinematic process of prey capturing including trigger mechanism and acting forces will be investigated using force measurement techniques combined with high-speed videography.
The overall aim of this project is to elucidate the biomechanical process of prey capturing in Odonata including the interaction of the other mouthparts as well as the differences in the eco-morphology of Odonata larvae in the context of food preferences by showing functional changes during ontogenesis.