BREEDING GOLDFISHES 51 



light place, and, if possible, where they may be protected from tem- 

 peratures below 60 or over 80 degrees. If stood in hot sun for several 

 hours in a shallow tray, the eggs are liable to be "cooked," and there- 

 fore spoiled. 



When the alevin or newly-hatched embryo bursts from the egg it 

 is a very weak creature. It appears a mere thread with a pair of eyes 

 at one end and small lump in the centre. This lump is the yolk sac 

 and serves as subsistence for the first few days. At first the alevin 

 can only swim by a few jerky motions, and has the power of sticking 

 wherever it touches. At the age of one day they are to be found 

 hanging on the plants and the sides of whatever receptacle they are in. 

 In from two to three days they are swimming freely. When the yolk 

 sac has been absorbed, which is in about three days, the babies will 

 need some food which has been previously prepared. The first nat- 

 ural food is a large variety of microscopic animals known under the 

 general heading of infusoria. These are present in all exposed water 

 which has stood a few days, but in order to have sufficient for fish food 

 it is necessary to have conditions favorable to their culture. This con- 

 sists mainly of vegetable decay. Dried and povv^dered lettuce or duck- 

 weed leaves or pea flour, sprinkled thickly on the water, produce good 

 results in a few days, kept in a warm place and a subdued light. Also 

 a quantity of hay over which boiling water is poured will soon pro- 

 duce the creatures. A low-power microscope or cheap magnifying 

 glass should be employed in this work. (See page 236.) After the 

 culture is apparent and the fish are swimming freely, occasional dips 

 of culture water should be put in with the young fry. Sometimes the 

 infusorians can be found freely in standing pools, particularly where 

 the water is not very clean, and where there are no cyclops or other 

 carnivorous crustaceans. One species, Brachiomts ruhcns, sometimes 

 occurs so thickly that the surface of the water appears to be covered 

 by a thin, rusty scum. When such a scum is observed in a stagnant 

 pool some of it should be placed in a small bottle and observed with 

 a low-power magnifying glass. If there is the appearance of dust-like 

 particles moving continuously about, it is very likely they are rotifers. 

 A thimbleful of this yellowish skimming contains more rotifers than 

 several gallons of ordinary stagnant water, and the breeder who can 

 locate this kind of live food when his fish are from one to three weeks 

 old is in good luck. Very small live food tends to keep the young 

 fishes more nearly a uniform size. If daphnia are fed at first, it is only 

 the more robust individuals that can eat them, and the result is a rap- 

 idly increasing disproportion in size that soon ends in cannibalism 

 unless the young giants are promptly placed by themselves. Small 



