ZOOLOGICAL SOCIETY BULLETIN 
SPINED LOACH 
Photograph by Dr. E. Bade 
fined to small quarters, would make it 
of the most desirable fishes for the home; but 
no plant is safe in the receptacle with it. 
one 
The facts concerning the date and circum- 
stances of its introduction in the United States, 
where New York Aquarium collectors discovered 
it in 1894 in the lake of Central Park, New 
York City, are unknown to science; but the 
fish has been transplanted by the Aquarium to 
other lakes as far west as Ohio, and as it is 
a prolific species, it will no doubt eventually 
become common in this country and_ possibly 
become a food species, as it has long been in 
Europe. The name “pearl roach” was given 
this fish at the Aquarium, before it was rec- 
ognized as the rudd. 
Its food in a state of na- 
ture consists of aquatic 
plants of all kinds, insects, 
snails and worms—especial- 
ly the red worm, Tubifec. 
In captivity it will eat al- 
most anything offered—yolk 
of hard-boiled egg, baked or 
boiled white potato, ant 
eggs, ground or boiled ver- 
micelli and cereals, chopped 
clams, beef, fish, ete. Nor- 
mally it attains a weight of 
two pounds and its scales 
become rough in the breed- 
ing season. It is a favorite 
morsel for the pike and 
other large fishes. 
Our experience with the 
pearl roach at the New 
Ue 
York 
that it 
satisfactorily 
indicates 
maintained 
the 
home that can provide run- 
for it, doing 
away altogether with plants 
except such as are thrown in 
for food. We have found it 
destructive to the plants 
commonly used in balanced 
aquaria, such as Sagittaria, 
Myriophyllum and Cabomba. 
Aquarium 
can be 
only in 
ning water 
EUROPEAN FISHES 
(Bitterling, Loach, Tench and 
Golden Ide.) 
One of the most interest- 
ing aquarium fishes is the 
Bitterling (Rhodeus 
rus) of Europe, sometimes 
brought to this country, and 
ama- 
famous for its strange habit of laying its eggs, 
which are few and large, within the shells of 
fresh-water mussels. Without mussels, it can- 
not be bred. 
There seems actually to exist an interchange 
of service by which the parasitic young mussels, 
liberated at the proper moment by their mother, 
become attached to the bitterling while she is 
depositing her eggs in the shell of the mussel, 
the young fishes and mussels leaving their re- 
spective hosts coincidently, in about one month. 
American mussels, as a rule, become parasitic 
upon larger fishes than the bitterling, and there 
is no American fish that lays its eggs in the 
The bitterling is therefore of 
mussel’s_ shell. 
BITTERLING 
Photograph by Dr. E. Bade. 
