154 
BULLETIN OF THE BUREAU OF FISHERIES 
the decline. The only evidence to suggest the maintenance of the species in the upper 
river is the increasing abundance of the egg mussel (“glassy-back” or “Missouri 
niggerhead,” Obovaria ellipsis ); the only fish now known to carry that mussel in its 
parasitic larval state is the shovelnose sturgeon, although there may be other hosts 
that have not been detected. 
The run of sturgeon in the river below Keokuk is said to be very variable; a good 
run is expected when the river is low during the spring, as in 1925 and 1926, when the 
expectations were fully realized. High water is said to be unfavorable. After the 
spawning period the fish continues to be taken in considerable but decreasing numbers, 
tember 9, 1916 
indicating that it spawns in this vicinity and then drifts southward, though probably 
some remain all year. For 1922, 1,080 pounds of shovelnose sturgeon were reported 
from Lake Pepin, but the fish has always been rare in that lake. 
That propagation now occurs above the dam is attested by the fact that very 
small sturgeon have been taken in the river at Fairport, Iowa, on several occasions. 
The Fairport station now has examples measuring in standard lengths, respectively, 
about 2 inches (52 millimeters, taken in July or August), 2.8 inches (71 millimeters, 
taken July 11, 1919), and 4.6 inches (116 millimeters), all taken at Fairport. 
White sturgeon. Parascaphirhynchus albus Forbes and Richardson 
This species is relatively rare, and virtually nothing is known of its habits. 
Local fishermen report taking them not infrequently, and say that they rarely contain 
