134 GOLDFISH VARIETIES AND 
Cypris. Incorrectly known as “hardshell daphnia,” Cypris forms an 
important article of fish diet. These crustacea inhabit stagnant pools, 
particularly those well stocked with decomposing vegetal matter. Al- 
though capable of swimming freely they are more apt to remain close to 
the bottom, but more especially to decaying wood. They are of a dull, 
purplish black color about twice the size of an ordinary pin-head. Inex- 
perienced observers frequently mistake them for Daphnia. Fishes do not 
appear to be quite so fond of them as of Daphnia but they are a good 
second choice. They are extremely hardy and will withstand dense 
overcrowding in the foulest of water. Under favorable conditions Cypris 
multiplies with astounding rapidity. They have been known to attack 
newly hatched fishes. 
Blood Worms. In freshwater pools nearly everywhere can be found 
deep-red, jointed worms about half an inch long. See figure 89. 
They usually stay at the bottom, living chiefly on decomposing vegetal 
matter. Often they will writhe their way awkwardly through the water in 
Fic. 89. Biroopworm (Larva of Chironomus) (Enlarged four times) 
a series of figure eights. They are the larve of midges and form an 
important article of diet for our native fishes. They are often found in 
large numbers in daphnia pools and should always be taken when possible. 
If too large for the young fish, they make choice morsels for the older ones. 
Tubifex Worms. These are small thread-like worms living in mud 
and sand. They form a tube or case below the surface, extending the 
upper ends of their bodies from this in search of small organic food, 
causing a circulation of water about themselves by a constant weaving 
' ¢ \ (AN 
Fic, 90. Tusirex Worms MAGNIFIED AND as THE Enps*Appear ABOVE THE BoTTOM 
motion. When alarmed they draw back into the case. They are exten- 
sively cultivated in Europe as a food for tropical fishes. A similar variety 
is often introduced into goldfish aquaria when feeding daphnia, where 
they become an unsightly nuisance, for goldfishes do not eat them. To 
