

272 BULLETIN OK THE BUREAU OF FISHERIES. 



below the surface of the water. With the growth of the young and the approach of 

 the colder weather they are gradually put down lower and lower, until in the winter 

 they are down nearly 10 inches, such a depth being naturally warmer than nearer the 

 very surface of the water. 



Among the young fish all sorts and conditions of the bodyand the fins are found — 

 that is, all forms intermediate between those closely resembling the normal crucian 

 carp with a long slender body, the unsplit tail and anal tins, etc, and those which are 

 extremely modified, as shown in the, varietal types described above. I fa lot of young 

 contains a large percentage of those with the unsplit tail, it is considered, from the 

 commercial standpoint, a failure, for these latter are only a fraction of the split-tailed 

 in price. In some experiments I have tried it was found that in selecting for breed- 

 ing the adidts which have the split anal tin give, on the whole, better results than 

 those with a single anal. It is needless to say that all undesirable ones are early 

 eliminated. 



All the young just hatched are dark in color, the bright colors coming only 

 later. A great deal of experience and skill is needed in making the gold-fish change 

 its color from black to red. If a person who is not an expert tries his hand at rais- 

 ing a lot of young gold fish he will find to his sorrow that the fish remain black and 

 do not assume bright colors, while those which may he from the very same lot of 

 eggs, hut have been under the care of a professional breeder, may have all donned 

 the beautiful hues. The essential points to lie attended to in bringing about this 

 change seem to be (1) that the young fish should be given plenty of food. (2) that 

 they should lie exposed to the sun's rays and be kept as warm as possible, and (.'!) that 

 the water of the pond in which the young are kept should be changed occasionally, 

 although sudden transfer from warm to cold water in the middle of the day is to be 

 avoided. The. change of color begins in about sixty to eighty days from the time of 

 hatching, and by the middle of August the fish should all have lost the dark pigment 

 and acquired bright colors. I am told a curious fact — that the fish which change 

 their color earliest are apt to be white or variegated white and red. while those that 

 change later are apt to be uniformly red. What can be the significance of such a 

 fact? I am also told that by the middle of August of the second year, all the 

 individuals, however obstinate, change their color. It is worth while determining 

 whether, even if the young are left to themselves and not given the care which 

 they receive at a breeder's, they will change color by the summer of tin 1 second year. 



White is commercially worthless and is ruthlessly weeded out. It is also said 

 that to improve the brightness of the color, the fish should be somewhat underfed 

 that is, should be given about 80 per cent of the ordinary feed. In Koriyama 

 they have the trick of bleaching out white spots in the red. by applying some mixture. 

 The result, I think, is not worth much. 



I have by no means exhausted the subject of the gold-fish; in fact, I doubt 

 whether anyone can write all the minute details of the art of gold-fish raising. But 

 I think 1 have -aid enough to show how full of interest gold-fish breeding is, not 

 only from the commercial or aesthetic point of view, but from the purely scientific 

 standpoint. A most casual glance shows it to be full of problem- which have ever 

 attracted the serious attention of biological investigators. 



