2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

machinery contributes to sensitive hearing and species-specific tuning in Drosophilid
flies. Also, data will be presented on how ChOs, on a more systemic level, contribute
to a fly’s ‘sense of time’ by providing sensory input for the animals’ circadian clocks.
Chair: Jakob Engelmann
�87 Adrian Klein A 701 / 14:00
Medullary lateral line units of the common rudd, Scardinius erythropthalmus, are
sensitive to Kármán vortex streets in terms of spike rate and spike pattern
Authors: Adrian Klein 1 , Jan Winkelnkemper, Horst Bleckmann
Affiliation: 1 University of Bonn, Institute for Zoology
Fish can sense water motions with their mechanosensory lateral line. Fish use the
lateral line for the detection of predators and prey, for schooling, collision avoidance
and energy efficient locomotion in unsteady flow. A cylinder placed in running water
alternatingly sheds columnar vortices (a Kármán vortex street) in a wide range of
Reynold numbers. Fish use Kármán vortex streets to reduce locomotory costs.
Navigating in hydrodynamic perturbations ? like those in a Kármán vortex street - is
complex and information about the hydrodynamic flow field is advantageous. Peak
spike frequency of primary lateral line afferents coincide with the vortex shedding
frequency, no increase in spike rate was found, however. Up to now it was not clear
whether and how vortex street information is processed in higher brain areas.
Therefore rudd, Scardinius erythropthalmus, were exposed to Kárman vortex streets.
Activity of medullary lateral line units correlated with unsteady flow signatures in
terms of spike pattern or spike rate or both. In contrast to the noisy spiking activity of
primary lateral line afferents, some medullary units showed a sharp representation of
each vortex in the vortex street. Synchronously obtained particle image velocimetry
was used to uncover a correlation map between the flow field and the neuronal
activity. A correlation map was found with peak similarity between the flow field
close to the fish and the neuronal responses of medullary lateral line units. Our data
show that some medullary units selectively process vortex street information.
Supported by the DFG (GRK1572)
�88 Hendrik Herzog A 701 / 14:15
Respiratory noise and lateral line function
Authors: Hendrik Herzog 1 , Joachim Mogdans 1 , Horst Bleckmann 1
Affiliation: 1 Institut für Zoologie, Universität Bonn
The lateral line system of fish responds to hydrodynamic stimuli and to hydrodynamic
noise. In electrophysiological experiments one source of noise that contaminates the
physiological data are the water motions generated by artificial respiration.
Visualization of the respiratory flow of Ide, Leuciscus idus, revealed a complex
pattern of turbulences with a predominantly rostrocaudally oriented flow of
approximately 3 cm/s. The belly of the Ide was more affected by the flow than the
back. Fluorescence staining revealed that neuromasts were not found directly in the
area of the highest velocities caused by the respiratory water flow.
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