Abstract
The author has done those experiments continously for the former report (Refference 1)) which was carried out “Centralizing method” and “Driving to one side method”. (Fig. 1.)
10 Goldfish Carassius auratus of an average total length of 4.0cm. were liberated in a wooden tank of 150cm. long, 26cm. wide and 8cm. water depth. For model nets of colours, 8 wooden frames were made to be stretched vinyle tube (dia. 1mm.) vertically at interval of 2.0cm. on each and the each frame had a colour of semi-transparent, yellow, white, green, pink, red, blue and except the 8th one which had fine white cotton thread.
The centralizing method was done with repeat of 40 times using all these 8 frames, and in all combinations of twoframes each. The sum of the total values were given in Table 1. and they were applied the chi-square test of statistics as expressing in the Table.
The observed values by the driving to one side method were expressed in Table 2. and Fig. 2. and the efficiency of driving was given in Table 3. and 4. Average values of them had been examined different significance by the F-table of statistics, seeing in Table 5.
As regards driving fishes on the two experiments, the frames of blue, pink and red are obviously more effective than the other frames of white, yellow, semi-transparent and white cotton thread.
As it is existing difference between the human and fishes on the senses of sight, he had examined visible distance in the water for each colour of vinyle frame taking method of as in Fig. 3. and the result is in Table 6. and Fig. 4.
Consequently, those results and quoting the result of the underwater fencing net (Refference 2)) were compared on order of effect of colours, seeing in Table 7. The orders of experiments (b) and (c) are accurate uniformity, as if the materials of model net are equal one and it had both taken method to drive fishes in. Though the (a) was done as fencing net unmoved, he had recognized few similarity between the orders of (a) and (d).
