TEOPICAL AQUARIUM FISHES 49 



for several generations and no fish varying from the desired type is 

 allowed to breed, the percentage of young coming true can be kept 

 very high. 



The begiimer should get his first experience in breeding the more 

 hardy varieties — the comet, for instance — ^but this stage passed he should 

 select none but the best breeding fish out of known good stock. The 

 best time to purchase new stock is in September and October, preference 

 being given to the larger fish about seven months old. At this period 

 the dealer-fancier is usually willing to sell off some of his larger old 

 fish. These are more showy than the young, but should not be selected 

 as breeders. In fact, none but the expert fancier who knows well what 

 he is about should purchase any fish over one year old. 



The fish often show signs of breeding early in the year. As pre- 

 viously stated the young males will start "driving" the females. If this 

 is observed before March, the sexes should be separated, as early spawns 

 are not to be desired, unless one has very special facilities. If the spawn- 

 ing can be delayed until May, results will be more satisfactory. The 

 reasons for this are that the harmful long cold spells are less likely to 

 occur and that living food can be obtained with more certainty. Spawn- 

 ing may be delayed by separating the sexes and by keeping the fish in 

 cool water. 



As spawning time approaches the fish should be well fed on nourish- 

 ing food. Finely chopped earthworms, carefully rinsed, are excellent. 

 Live daphnia are even better. When the breeders have been selected 

 they should be placed togther by themselves. If possible there should 

 be three males to one female. This insures a higher percentage of 

 fertilized eggs than if only one male is used. If the definite results of a 

 certain cross are wanted then use only one male. A second female 

 not spawning should never be present, as she will devour the spawn. 



Papier mache tubs are very nice for spawning in, but seasoned wood 

 tubs or tanks will do. The aquarium may be used, or the spawning net 

 shown on page 231. 



Should there be no spawn after the fish have been together several 

 days, remove about a quarter of the water daily and replace by fresh. 

 This is very stimwlating. Some intimation of an approaching spawning 

 may be had by the fact that the males occasionally "drive" the ripe 

 female for several days before the spawning takes place. This usually 

 increases in intensity the evening before, and when spawning is in full 

 swing it develops into a wild chase punctuated by short periods of rest. 

 So vigorous is the swimming at this time that fishes with large fin 

 development generally have their fins torn and frayed. Males with 

 shorter caudal fins (tails) are the more rapid, swimmers and their fins 



