The spectral sensitivity of eye movements in response to light flashes in Daphnia magna

The crustacean Daphnia magna responds to a flash of light with a ventral rotation of its compound eye; this behavior is termed eye flick. The authors determined the spectral sensitivity for the threshold of eye flick in response to light flashes having three different spatial characteristics. All three stimuli extended 30 degree to the right and to the left of the animal's midplane. No circadian or other periodic changes in threshold spectral sensitivity were observed. The results are discussed in terms of current knowledge of the spectral classes of photoreceptors found in the Daphnia compound eye.