Abstract: In this paper, the relationships between natural light cycle and cycles of reproduction and molting of cage-raised fable were described. The correlation was analysed between testis development of male sable and natural light cycle. The seasonal variation of serum progesterone level in pregnancy sables was also determined. Artificial light was also used in the study. It was proved that ultraviolet light (280—320nm) has an important effect on the reproduction of sable. All the researches in this paper demonstrated that light, as an important ecological factor, affected the reproduction and molting of many kinds of animal.

Key words: Cadmium, Chemical pattern, Grass, Bio-accumulation