Abstract
Melanophores of young Rhodeus ocellatus ocellatus have the ability to respond by melanosome dispersion to the direct action of visible light. The effective wavelength within visible light region for inducing melanosome dispersion was investigated using melanophores located around the base of the dorsal fin of young fish set on the stage of a light microscope. The melanophores were exposed to light of various wavelengths (420-680nm) but of the same intensity by placing interference filters under the condenser diaphragm. The most effective wavelength was about 420nm. Longer wavelengths were less effective for the induction of melanosome dispersion.
