THE PROPAGATION OF THE GOLDFISH 



The greater part of it is vertical and median, but its lower portion occurs 

 double, (the tripod tail,) which in some cases extends further upwards, (the 

 web tail.) In other instances the furrow may reach the dorsal edge of the 

 tail and thus divide it into two halves, which then expand right and left. 

 These. halves may or may not be connected at the median line, at the 

 dorsal edge; in the former case, the tail is represented by a more or less 

 horizontally expanded single piece, (the dolphin tail;) in the latter case it 

 is distinctly paired, (the double tail.) Fig. 57. 



Next to the caudal fin the anal fin undergoes a remarkable variation. 

 It is either median and normal or distinctly paired. In the former case, 

 especially when the caudal fin is also normal, the goldfish closely resembles 

 the carp. In the double form of the anal fin, bony structures similar to 

 those of the single fin are present in pairs. These double fins often make a 

 flapping motion serving the same function as the ventral fins. Examination 

 of the embrios of these breeds of fishes show that the double caudal and 

 anal fins are laid out as two longitudinal folds or thicknesses along the ven- 

 tral side of the post-anal section ofthe body, which diverge at a later period 

 and form paired caudal and anal fins. The internal structures of these 

 parts are also paired. In some ofthe breeds the anal fin is entirely absent 

 and others have been developed which are devoid of dorsal fins, while the 

 Egg-fish has neither dorsal nor anal fins. 



Breeding. It is proposed to treat of tank culture first and later of 

 the basin or pool and pond or lake culture, these latter terms being applied 

 to the smaller brick or cement basins and pools or those with earthen or 

 boarded sides, and the larger natural or artificial ponds and lakes. 



When the breeding is conducted indoors or in a greenhouse the season 

 is earlier than in the open air and spawnings may begin in February, while 

 out-of-doors or in the pond, in a temperate climate, the fishes may not 

 mature the spawn till April, May, or June, after which it may be continu- 

 ous, at short intervals, until the advent of cold weather. Spawning is 

 also dependent upon the temperature ofthe water and rarely begins until 

 it has reached 60° F. 



The period of rest between spawning varies with the fishes and may 

 be but a few days or several weeks, dependent upon their vigor and the 

 temperature of the water. Spawning may occur two days in succession, 

 or at an interval of several days, if the weather becomes colder, to be re- 

 sumed when the water becomes warmer. Of this the surest guide is the 

 appearance ofthe female and the action of the male, and trials with the latter 

 should be undertaken, the fishes being again separated if no spawn results 

 in a day or two. An occasional change of males is also advisable. Stimu- 



98 



