98 ZOOLOGICAL SOCIETY BULLETIN 
Most diseases are contagious and sick fishes 
should be segregated to save the remainder. 
Nets should be sterilized by dipping them into 
boiling water or a disinfecting solution. 
If a fish is ailing and the trouble cannot be 
readily diagnosed, regular salt or permanganate 
baths should be given; but if the specimen is 
not benefited and appears to be suffering, it is 
best to put it out of its misery. 
Turks Island salt is generally preferable to 
table salt, which may contain some ingredients 
to prevent caking. Sick fishes can be placed 
in a weak solution, changed daily, and if they 
fail to respond, the strength of the solution may 
be gradually increased until double strength 
is used. 
Shallow water, in a spot away from the 
bright light, is best for specimens under treat- 
ment. 
INJURIES 
For fishes that have received slight injuries, 
scales torn off, ete., it is best to remove the 
specimens from the water and pour on the 
wounds a strong solution of permanganate of 
potassium, returning the fishes at once to their 
native element and using a separate dish until 
the permanganate washes off, when they may be 
placed in their customary aquarium. Infection 
will not set in where this treatment is used in 
time. 
When a fish is removed from the water its 
gills should be kept moist with a wet sponge 
or cloth, and the less handling with the fingers, 
the better. Removal of slime that naturally pro- 
tects the scales, may ensue from the touch of 
a finger, thus rendering the fish liable to in- 
fection. Too little or too much slime on a fish 
appear to be equally dangerous. Mr. Harvey 
Van Cott found that a sick fish secretes more 
slime than a healthy one, thus allowing parasites 
to enter and protect themselves until they have 
time to bore through the epidermis. A healthy 
fish could brush them off. 
Wuite 
Funcus—Saprolegnia 
One of the commonest ills of captive fishes 
is the development of white tufts like small 
bunches of cotton, on various parts of the body. 
Fishes fed on one kind of food exclusively, un- 
less that food is beef, seem specially liable to 
this disease. At the Aquarium it has been obser- 
ved that if perch are fed exclusively on clams, 
they develop fungus; less trouble ensues if 
they are fed on a mixed diet of clams and beef 
heart, and no trouble when fed exclusively on 
beef heart. Fishes like common pond fishes 
and goldfishes, have been kept successfully in 
home aquaria for many years on an exclusive 
diet of beef, but, like other folks, they like a 
variety of foods. 
White fungus also results from other un- 
healthy conditions such as lack of exygen, sud- 
den changes of temperature, food decaying in 
the bottom of the tank, ete. If the scales are 
torn off or their protecting slime removed by 
improper handling, fungus is likely to develon 
The white fungus, sometimes called water mold, 
has lost its color by adaptation to a parasitic 
existence. Dr. E. Bade has found that, as the 
fungus is a plant thriving only in cool bright 
places, the placing of an infected fish in warm 
shallow water in a dark place, will effect a cure. 
At the Aquarium, where a collection of fishes 
may have become fungused through bruises 
caused by long journeys, we have found daily 
treatment in weak permanganate solution the 
best for soft-scaled fishes like goldfishes. For 
fishes with tough scales, salt treatment is most 
efficacious, and we inject a stream of salt water 
into their tank continuously until they are cured, 
which may take several weeks. The same effect 
may be accomplished in the case of toy fishes 
by putting them in a weak salt solution. 
An effective remedy where the fungus is at- 
tached to the body away from the head, is to 
dip the affected part in a 50 percent. solution 
ot peroxide of hydrogen, or a 50 percent. solution 
of kerosene oil. ‘This may be repeated once or 
twice, keeping the fish’s gills moist while the 
operation is in progress. 
Once the fungus reaches the gills, the case 
is as good as hopeless. The gills soon become 
filled and close up. 
There is a black fungus which we have not 
seen at the Aquarium but which is said to yield 
to the same treatment as that for white fungus. 
Wuire Prrs in Scaves anv Fins 
Tue SHAKES 
This disease presents, at a superficial glance, 
an appearance similar to that of white fungus, 
but on closer examination proves to be pits and 
not tufts of white, on the scales and fins of the 
fish. It is caused by an animal parasite, one 
of the protozoans, by whose name it is common- 
ly known—Ichthyophthirius multifilius. It is 
most frequently found in fishes of the carp, 
trout and catfish families, the goldfish belonging 
to the first of these. 
The life history of this parasite was studied 
fifty years ago, but it was not until Dr. C. W. 
Stiles was appointed by the U. S. Government 
at the time of the Columbian Exposition, to 
