62 ZOOLOGICAL SOCIETY BULLETIN 
DAPHNIA CYPRIS 
Water fleas. Equalized in size for clearness. Daphnia is the largest and 
Cypris is the smallest of the three. All are visible to the naked eye. 
Drawn by Ida M. Mellen. 
CYCLOPS 
Some young goldfishes have been observed to 
feed better on bright than on dark days, and all 
goldfishes feed better in cool than in warm 
water. The infusoria may be alternated with 
a sprinkling of rice flour on the surface, the 
finest dust from soda or graham crackers, oat- 
meal broth, a little blood pressed from raw 
beef, or juice similarly pressed from a clam, 
oyster or mussel. Algae growing on old plants 
or the sides of tanks is much appreciated, also 
the fine dust from the various prepared fish 
foods such as dried ground shrimp and ground 
puppy biscuit. There are excellent preparations 
of baby fish food on the market, two different 
varieties of which may be bought and mixed, or 
fed alternately. 
All foods must be given sparingly. The rule 
of feeding little and feeding often, cannot be 
improved upon. 
Oatmeal broth or the yolk of a hard-boiled 
egg strained through cheesecloth or a fine tea- 
strainer furnishes a splendid food during the 
first three months—the most delicate period in 
the goldfish’s life. It will find some food sub- 
stances in clean earth which can be suspended 
in a saucer. 
During the first six weeks the young fishes 
are a nondescript gray color, assuming the adult 
form and coloration at about the end of this 
period which is a trying one for the breeder, 
not so much because of the difficulty of feeding 
them properly, but because it frequently hap- 
pens that hundreds of the fry—sometimes the 
entire spawning—are lost through a sickness 
called “‘gill trouble,” “‘gill fever,’ or “‘gill con- 
gestion.” The gills become inflamed and swollen 
and the fishes soon begin to die off. Some 
breeders have thought that an exclusive diet of 
infusoria and artificial foods during the first six 
weeks will prevent this sickness, others have at- 
tributed it solely to overcrowding. The exact 
cause is uncertain, but if the food and character 
of the water are correct, it is believed that a 
draft playing over the surface where the young 
congregate, may chill them and bring on the 
condition, which corresponds, of course, to a 
cold on the lungs in higher animals, and is 
probably equally contagious. They can be pro- 
tected against this source of danger by screen- 
ing the top of the tank. A common window 
ventilator of unbleached muslin laid across the 
top will serve the purpose, or, for a circular 
tank, one can make a cover by sewing some mus- 
lin onto a pasteboard hoop cut to fit. 
Prevention is worth more than any cure, but 
if the trouble has started, it may be checked by 
placing the fishes in a weak solution of perman- 
ganate of potassium (three grains to a quart of 
water—meaning by particle one 
thirty-second of an inch long), or in a one to 
10,000% solution of sulphate of copper, leaving 
them in the solution a quarter of an hour, then 
diluting it by half and leaving them in for an 
“grain” a 
hour unless they begin to die or appear to suffer, 
COLLECTING 
Photograph by Ida*°M. Mellen. 
