COMMON FISHES OF MISSISSIPPI RIVER 
163 
net near the unfinished half of the power house on the evening of May 30, 1915; 
on June 26 of that year 28 were taken in the same locality. The fish was found about 
Keokuk from February to August and probably spawns in February or March. 
There was no indication that the dam interfered with its habits. Many years before 
the dam was built Forbes and Richardson wrote: 
This large and handsome silver-coated fish is now too rare in Illinois to have any special signifi- 
cance in our waters. Some years ago it was much more abundant than now in the Mississippi and 
the Ohio, as many as a thousand pounds at a time having been caught, according to Mr. Ashlock, 
from the former river near Alton and the latter at Cairo. 
White-eyed Mooneye. Hiodon tergisus Le Sueur 
“toothed herring” 
Although said to be very abundant in the Ohio River and in Lake Erie (Forbes 
and Richardson, 1908), the white-eyed mooneye was found to be much less common in 
the vicinity of Keokuk than the other species. The two fishes are apparently not 
distinguished by the fishermen of that region. It is smaller than the goldeye; the 
largest taken at Keokuk was 30 centimeters (12 inches) in length, but a somewhat 
longer specijnen was taken in Lake Pepin. Fish were examined by Stringham for 
reproductive condition in each month from February to August (except June). 
Sexually mature fish with eggs flowing on pressure were taken at Keokuk on March 15. 
The fish varied in length from 23 to 28 centimeters (9.5 to 11 inches), and the eggs 
were 1.7 to 2.3 millimeters in diameter. 
The contents of the stomachs of a dozen examples that were examined for us by 
Doctor Muttkowski comprised chiefly May-fly larvse of various kinds (Hexagenia, 
Ephemera, Heptagenia, Siphlurus, Bsetinse, etc.), black-fly larvse and pupse 
(Simulium), caddis-fly larvse (Hydropsyche), dytiscid beetles, and water boatmen 
(Corixa). Forbes and Richardson say that the food is chiefly insects and their 
larvse, mollusks, and small minnows. It is described as a vigorous biter and gamey 
on the hook. It does not, however, seem to have the good qualities as a fresh food 
fish that the other species possess. 
On several occasions the author has taken mooneye in Lake Pepin, and in all 
cases the species was tergisus, which we assume to be the more common species in that 
