The sensory biology of host detection in the parasitic salmon louse: electrophysiological and behavioura linvestigations

We propose to extend our previous work on the chemical and visual cues underlying host location by the salmon louse by 1. determining the threshold responses required for chemical signals to induce oriented movement towards a point (e.g. a fish) 2.determine the threshold levels necessary to elicit behavioural responses to light flashes emanating from the silvered sides of the salmon host 3. determine the frequency with which light flashes, and shadows, can be presented to lice without engendering habituation of the response 4. establish the distances over which light and chemical cues could influence salmon lice behaviour in their natural environment. Determining threshold responses is necessary to define the intensity of the signal that must be produced to attract lice in their natural environment. Determining the habituation response is important so that the signal is not presented at a frequency tha t results in the lice ignoring it. The ultimate goal of this research is to develop a field-deployable trap that will fool the salmon louse into swimming away from salmon sea cages, thereby disrupting hos location and settlement.