Extraokulare Steuerung des Farbwechsels bei Kaulquappen

Summary In tadpoles ofRana temporaria, the light threshold for the pigment dispersal of melanophores was determined. The darkening reaction of previously dark-adapted animals is not affected by removal of the lateral eyes and starts with illumination of about 0.01 lm/m². This is about 2 log units below the threshold of the direct effect of light on tailfin-melanophores inXenopus tadpoles and about 2 log units above the light threshold of the steady discharge of the exposed diencephalon in adult frogs. The finding suggests that in tadpoles the pineal organ controls the function of melanophores.