BREEDING HABITS OE THE YELLOW CAT-FISH. 
By HUGH M. SMITH and L. G. HARRON 
In view of the paucity of information in regard to the spawning habits of cat- 
fishes, and owing to the possible inauguration of cat-fish culture in response to a wide- 
spread demand, we think it worth while to present these observations on one of the 
most important members of the family. The notes may be taken in conjunction 
with Dr. Albert C. Eycleshymer’s “ Observations on the breeding habits of Ameiurus 
nebulosus ,” published in the American Naturalist for November, 1901. 
On duly 3, 1902, it was observed that among a lot of yellow cat-fish ( Ameiurus 
nebulosus) from the Potomac River near Washington, which had been in the Fish 
Commission aquarium since May 19, 1902, two had paired and exhibited breeding 
tendencies. They had withdrawn to one end of the aquarium tank and maintained 
themselves there, the male driving away any others which approached. The other 
fish were thereupon removed and the two in question left unmolested. They were 
kept under daily observation, and their behavior furnished the principal data on 
which this paper is based. In the latter part of July another pair of fish in the same lot 
showed an inclination to spawn and afforded additional information, as did also a lot 
of eggs of the same species found in a pool in the Fish Commission grounds on June 16; 
these eggs, which were about ready to hatch, were removed to an aquarium, where 
two-thirds hatched the same night, the others being dead the next morning. 
Nest-making . — The aquarium in which the fish were held was 5 feet long and 16 
inches wide on the bottom and 18 inches high, the posterior wall inclining obliquely 
backward so that at the surface of the water the tank was 2 feet I inches wide. The 
front was of solid glass, and the sides, bottom, and back were of slate. The bottom 
was covered with gravel and a little sand to the depth of 11 or 2 inches. 
The nest-making, as modified by the artificial conditions of the aquarium, con- 
sisted in removing all the stones and sand from one end and keeping the slate bottom 
scrupulously clean from all foreign objects, even the smallest particles of food, sedi- 
ment, etc. In moving the pebbles, which were mostly from one-half to three-fourths 
of an inch in diameter, the fish took a vertical or slightly oblique position and 
sucked a pebble into the mouth, usually beyond the lips and out of sight, then swam 
toward the other end of the tank and dropped it by an expulsive or blowing effort. 
Sometimes the gravels were carried only a few inches and sometimes the entire 
length of the aquarium. Usually the fish swam horizontally near the bottom when 
carrying a stone, but sometimes turned obliquely upward and dropped it from near 
the surface. Both fish participated in this operation. The removal of finer sediment 
was effected by a quick lateral movement of the body which caused a whirl that lifted 
and floated the particles beyond the limits of the nest. 
The pair of fish more particularly under consideration, during the first night they 
were in the aquarium, removed all the gravel from over a space nearly 2 feet long and 
li feet wide, upward of a gallon of stones being transferred as described. After 
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