COMMON FISHES OF MISSISSIPPI RIVER 
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larly taken there, do not have eggs large enough for caviar. About Keokuk it is 
found with eggs suitable for caviar from late summer or fall until early June. 7 In 1915 
the last can of caviar was shipped from Warsaw on June 7, but the eggs may have 
been taken several days earlier; in 1916 the last shipment was made on June 13. In 
the latter year a small shipment was made from Canton, Mo., on June 21. The 
fish itself continues to be taken in substantial though lessened numbers for another 
month. 
Luther McAdams, of Keokuk, names May 10 as the height of the season for eggs 
of sturgeon. At about that date, using heavily loaded trammel nets drifting in the 
“channel lick,” about 1.5 miles below the bridge at Keokuk, he has taken sturgeon in 
quantity with eggs and milt flowing from them as they were removed from the net. 
The nets were dragging the bottom, as evidenced by the fact that small rocks in 
numbers were caught in the pockets of the net. 
The sturgeon was about fourth in abundance among the fish found immediately 
below the dam by Surber in 1913. (Coker, 1914, p. 10.) This was a month after the 
end of the spawning season. Such degree of abundance is not remarkable. The two 
principal dealers at Keokuk and Warsaw stated that the fish had been commoner 
after than before the erection of the power station. Surface observations are of no 
significance because the fish is of bottom habit and rarely seen at the surface; the 
author has never seen it free in the water. In the immediate neighborhood of the 
power plant, according to our observation, it is infrequently taken, although set lines 
are used there regularly; near the dam an example was caught in a trammel net on 
June 22, 1915, and another in a gill net on May 30, 1916. Three-quarters of a mile 
to a mile (1% kilometers) below they were caught in set lines. From here to Warsaw 
the principal fishery existed, being prosecuted with trammel nets drifted in the current. 
Of all the recorded catches of fish about Keokuk, 1 1 contained this species, and all of 
these but one were products of the trammel net. The capture of a specimen in a 
slough (behind Mud Island) excited the interest (June 25, 1915) of the fishermen 
because the species is virtually never taken except in the river. It is known as a fish 
of the current. 
Examples were seen about Keokuk during the years 1915, 1916, or 1917, in each 
month from February to September, inclusive. Dealers and fishermen said that it was 
occasionally taken in quantity during the winter. When weekly inquiries of the mar- 
kets were started the season was almost ended; the quantities reported by the three 
markets, given to the nearest hundred pounds, are shown in Figure 4. 
The “ hackleback,” as it is appropriately called, is reported to be less abundant on 
Keokuk Lake than it used to be on the river. The commercial yields of hackleback 
from Lake Keokuk in all years of the survey were insignificant, being 1,900 pounds 
in 1914, 454 pounds in 1917, 600 pounds in 1922, and none in 1927. Monthly inquiries 
during the open season of 1916 showed that from 100 to several hundred pounds a 
month were taken at Burlington. At Fort Madison, where the current is slight, a 
few were taken, but never as much as a hundred pounds in a month. Farther down, 
at Montrose, Iowa, the fish is rarely taken, no instance having come to the attention 
of the writers. These facts reflect the strong preference of the species for a current. 
All reports in 1926 indicated scarcity of hackleback in the lake and the river imme- 
diately above. George E. Smith, at Fairport, said in 1926 that there were still seasons 
of plenty and seasons of scarcity, but he believed that on the whole sturgeon were on 
7 George E. Smith, at Fairport, said that sturgeon with roe suitable for caviar are taken in fall, winter, and spring. 
