Factors Influencing the Growth of Integumentary Pigment in Fishes. I. The Role of Light. ∗ †

Abstract

Summary

1. In addition to a favorable internal environment in the cell, light is necessary for the development of melanin in melanophores of intact scales.

2. Light passing directly through glass bottomed tanks onto the lower surface of the flounders was the most effective in producing melanophores. This means of illumination delivered the most intense light to the ventral surface of the fish and could be most accurately measured.

3. The use of opaque masks indicates that light affects the cell directly to produce melanin.

4. The melanination of regenerating scales is apparently not dependent upon the presence of light. Investigation of this special problem is being continued.