COMMON FISHES OF MISSISSIPPI RIVER 
177 
by the predacious older fish. In the following year (the experiment being then under 
the supervision of A. F. Shira and H. L. Canfield), 34 fish, including some of the 
original brood stock, were placed in a larger pond similarly equipped with nesting 
places. Again no signs of spawning could be seen from the banks, but early in July 
the pond was slowly drained, and on July 6, when the greater part of the bottom was 
exposed, Superintendent Canfield saw a catfish of 3 or 4 pounds weight with a school 
of fry near by. Further examination showed that there were still fry in one of the 
kegs, and in another a glutinous mass of eggs adhering to the lower side of the keg, 
the individual eggs averaging 3.53 millimeters (about 0.14 inch) in diameter. It was 
found possible to hatch the eggs and to rear the young in ponds. After that time the 
experiment was repeated many times and with general success, except that the num- 
ber of nests occupied and the number of young obtained was disproportionately 
small relative to the number of available breeders. The channel catfish, however, 
is not supposed to be primarily adapted to life in small ponds. Nevertheless, the 
experiments established the practicability of the propagation of spotted catfish under 
artificial conditions. 
In 1926 the testimony was universal that channel catfish had greatly increased in 
abundance in the river above the dam, from Keokuk to Oquakwa at least. The 
evidence of the statistical surveys, referring to all species of catfish, is to the same 
effect. 
The channel catfish, as its popular name implies, likes swiftly flowing water but is 
not restricted to regions of strong current. It is very common, for example, in Lake 
Pepin. It must have migratory habits at one or another stage of its life, for, in the 
words of Forbes and Richardson (1908), “the young of this species have * * * a 
much wider range than the adults and are frequently abundant in headwater streams 
and creeks, in which full-grown individuals are never taken.” 
Spotted catfish are taken in all parts of the river about Keokuk and by nearly or 
quite every kind of tackle used. Examples were seen in each month except November 
and December, and it is believed that they are present all the year. While the fish 
are evidently nomadic, there was found no evidence of migratory movements such as 
would be significantly hampered by the dam. 
Niggerlip. Ictalurus anguilla Evermann and Kendall 
PONEHEAD 
The niggerlip catfish, or ponehead, well known to fishermen throughout the 
greater part of the course of the river, has proven somewhat elusive to the student of 
fishes. It is so evidently different in appearance from any other catfish as to be 
readily recognizable to the uninitiated. On the other hand, it conforms in so many 
diagnostic characters to the spotted catfish as to be puzzling to the scientific analyst. 
Externally viewed, it differs from the latter fish chiefly in proportions, in color, and in 
appearance of the integument— characters that are manifestly difficult of strict 
definition; as yet there are no adequate expressions of the variable proportions of 
either punctatus or anguilla, and both species undoubtedly manifest different pro- 
portions and peculiarities of appearance at different ages and perhaps at different 
seasons. 
Stringham encountered no examples of the niggerlip at Keokuk, unless they were 
the fish locally and inappropriately called “bullheads,” which were thought to be a 
phase of the variable channel catfish. Forbes and Richardson (1908) associate the 
