Effect of Light on the Hatching of Fish-egg

Abstract

In order to examine the effect of various color rays on hatching of fishegg, colorless, blue, red, orange and dark color rays were used on the hatching of eggs of Wakasagi (Hypomeius olides), Ugui (Tribo'odon hakueucsis), Carp (Cyprinus caupis), and gold fish (Carassius carassius).
The result of experimints is shown as follows:
1. In the case of eggs of Wakasagi, there was no difference on the rate of hatching when they were exposed in orange, red and dark color rays, and other rays showed a good result on hatching. But blue color ray proved no good result and colorles ray was the worst (Table 1).
2. In the experiment of eggs of Ugui, blue, orange and red color were produced good results. There was no difference on rate of hatching among these three color rays. The dark color ray was not good result and the colorless ray was the worst
3. In the case of eggs of carp and gold fish, I can not recon nize the difference of the rate of hatching among those color rays (Table 3 & 4).
4. According to the different fish species and kinds of color rays, there was some difference in the average of days of ha ?? ching and mean variation of days of hatching. On the whole, however, in the case of good percentage of hatching, the value of variation was small.