HABITS OF SOME OF THE COMMERCIAL CAT-FISHES. 
409 
this fish is not much affected by the refuse from factories. After consulting with Prof. Spencer F. 
Baird, 100 young cat-fish arrived at Antwerp in November, 1884. By the advice of Professor Baird, 
these young cat-fish were not immediately placed in the river, but first in the large basins of the large 
aquarium. It is only after these fish have reached maturity in the aquarium and have spawned there 
that the young generation should be transferred to the river. This was done, and the young cat-fish 
received from America have provisionally been placed partly in a small pond in the Botanical Garden 
at Ghent, and partly in the Victoria Regia basin in the same garden. The selection of the last place 
we do not consider fortunate, as the temperature of the water in this basin is certainly much too high 
for these fish. At present there are in the Amsterdam aquarium 45 cat-fish, brought direct from New 
York and placed in a special basin with the hope that they will reach maturity and propagate their 
species. At present these fish measure from 4 to 6 inches long. 
In the same bulletin, on page 138, appears the following, by Dr. Jousset de 
Bellesme, on the American cat-fish in the Troeadero Aquarium of Paris: 
These fish, which measured 12 cm. (about 4f inches) in length, were, in the beginning, owing to 
their small size, placed in one of the tanks for young fish in the aquarium and remained there till 
November, 1885, when they were put in the large basin, No. 6. 
They were first fed with raw meat, but as they did not seem to take very well to this kind of food 
they were fed on raw fish chopped fine, which they appeared to like. As soon as they were trans- 
ferred to the large basin they were fed on live fish. 
The water at the disposal of the aquarium is that which comes from the Vanne, whose temperature 
is 15° C. (59° F. ) in August and 9° C. (48.2° F. ) in December. It is hardly probable that this tem- 
perature is sufficiently high for the reproduction of the cat-fish. At any rate, those which we have in 
our aquarium, no matter to what variety they belong, have never spawned. 
When the American cat-fish were transferred to basin No. 6 they were all alive and well, although 
they had not grown perceptibly. Since that time none of them have died, as far as we have been 
able to observe, for these fish have a habit of keeping in their holes and never coming out during the 
day, so that they are hardly ever seen. In basin No. 1 we had some of considerable size, and in order 
to assure ourselves of their existence it became necessary to empty the basin and carefully search for 
them at the bottom between the rocks. Even then we did not always succeed in finding them. I 
have, therefore, reason to believe that seven cat-fish which the Acclimatization Society has given us 
are still in existence, and the first time the basin is emptied I will search for them again in order to 
make sure. 
Cat-fish are preeminently a pool' man’s fish. They not only afford him a cheap 
food-fish, but become so abundant in time and there is so much demand for them 
that they afford a paying industry, notwithstanding their cheapness. They may lie 
raised in artificial ponds or in ponds unsuited to other fish. They propagate rapidly 
and prolific-ally and grow fast. Therefore there can be no objection to the introduc- 
tion of them into waters unsuited to other fishes or in which other fishes do not occur, 
provided there is no danger of escape into waters where they would prove an unde- 
sirable acquisition owing to the objectionable characters already enumerated. The 
past attempts to introduce them into European waters, from the records cited, would 
seem hardly extensive enough to prove their adaptability or unsuitability to those 
waters 
