298 REPORT OF COMMISSIONER OF FISH AND FISHERIES 
the seals attacked the sturgeon for the purpose of eating it or simply 
in a playful manner, but its fins and tail showed evidences of the teeth 
of the seals from time to time during its captivity. 
FOOD. 
The food of the fresh-water fishes consisted largely of round beef- 
steak and liver chopped in various sizes to meet the requirements of 
the fish. In addition to this, when possible, large supplies of minnows 
and other small fishes were provided from the neighboring waters. 
This not only gives the fish a desirable change of diet, but it is almost 
impossible to teach the black bass and crappie to take liver and steak, 
which naturally results in the loss of large numbers. As but few of 
the salt-water fishes will take liver or steak, clams, oysters, fiddler 
crabs, and other material of this character were provided. 
DISEASES. 
The aquarial exhibit at Buffalo had much difficulty with fungus. 
The waters of Lake Erie appear to be well supplied with the spores 
of the fresh-water Saprolegnia. This vegetable parasite is an enemy 
which fish-culturists constantly encounter more or less. At Buffalo 
its attacks were unusually persistent, and constant attention was 
required to keep it within bounds. 
The time-honored remedy for fungus is common salt, which was 
early adopted in fish-cultural work and has served with reasonable 
efficacy in preventing the parasite from gaining a foothold, but which 
is not particularly rapid and energetic in its action, and requires 
constant use in large amounts, involving considerable labor, care, 
and attention. In the endeavor to find a better remedy, potassium 
permanganate was selected for a trial, from its reported successful use 
in England when introduced constantly or for a considerable time into 
the water. This method was objectionable in the aquaria on account 
of the color imparted to the water, and was impracticable for other 
reasons also, the fish being able to endure only a short time. The 
permanganate is a powerful disinfectant and it proved to be readily 
fatal to the vegetative filaments of the fungus when freely exposed to 
the action of a dilution as small as 0.05 per cent for one minute. Trout 
will usually survive this treatment, and the filaments hanging from 
the body are killed. But this does not end the matter, for a ring of 
fresh growth is soon seen surrounding the original patch of fungus, 
which is not superficially attached, but vegetates into the skin itself 
and is protected by it and by the slime which covers the fish from 
head to tail. To reach this with a solution of any active substance 
and leave the fish uninjured is a difficult matter. The fish will not 
endure a material increase in the strength of the solution or the time 
of exposure, and there is no safe margin between a strength which is 
