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BULLETIN OF THE BUREAU OF FISHERIES 
Lake sturgeon. Acipenser rubicundus Le Sueur 4 
ROCK sturgeon; rubbernose sturgeon 
The lake sturgeon, though formerly abundant in all the Great Lakes region and 
the Mississippi Basin, has for a long time been in process of extermination owing, in 
the first instance, to wasteful destruction by fishermen in past years when no use for 
them was known and they were regarded only as unmitigated nuisances if captured 
in trap nets or seines. 5 * * 8 
The lake sturgeon attains a size of about 6 feet in the Great Lakes. There are 
reports, indeed, of 9-foot sturgeon, but the average length of mature fish is less than 
5 feet. (Milner, 1873.) The food, according to many observers, consists of small 
shellfish, gastropods (Milner), crawfish (Smith, 1892), insect larvae (Woolman; see 
Evermann and Latimer, 1910), larvae of May flies (Wagner, 1908), and worms (Ryder, 
1890). Fish eggs have been found in the stomachs, but not frequently, and the eggs 
observed have been mostly eggs of the sturgeon. 
All observations indicate that lake sturgeon approach the shores and ascend 
smaller rivers at the spawning season, which in the more southern of the Great Lakes 
occurs in the month of June. When in the spawning migration they frequently 
“break” the surface and even leap entirely clear of the water. (Milner, 1873.) The 
large eggs are strongly adhesive. Up to the present time very slight success has 
rewarded the many efforts that have been made to apply methods of artificial propa- 
gation, not only because the eggs are troublesome to handle but also because almost 
invariably great difficulty is encountered in securing ripe fish of both sexes at the same 
time. Barney (1924) has suggested that the lake sturgeon does not spawn yearly 
but has an extended reproductive cycle, since most of the adult fish caught in Lake 
Pokegama, Minn., during the breeding season were unripe. 
As concerns the Mississippi River in the section near and above the Keokuk 
dam, Forbes and Richardson (1908, p. 25), writing in 1908, five years before the con- 
struction of the dam, said : 
Lake sturgeon have of late years been steadily decreasing and are now only rarely taken in the 
Mississippi on our own borders (those of the State of Illinois) and are seldom caught in Illinois. 
Fishermen at Alton now see but 5 or 6 a year that weigh over 10 pounds, whereas 15 years ago 40 
or 50 large ones, weighing from 50 to 100 pounds, were taken each season. 
4 Hubbs (1917) suggests that the name Acipenser fulvescens has priority over rubicundus. However, as Rafinesque gives no 
recognizable description of the species that he designates A. fulvescens, we think the suggestion should not be adopted. Identifica- 
tion of Rafinesque’s species can be made only on the assumption that no other species of sturgeon could have been at the place 
where he collected an assumption that may be true but that clearly does not admit of scientific determination. 
8 Meek (1890) says (for Iowa): “The species is common in the Mississippi River in the spring; rather scarce at other times of 
the year.” But, again, referring to the same observations, he says in 1892 (p. 221): “Not common; more*abundant in the spring.” 
He knew of no postivc record for any other stream within the State. Woolman (1892) describes the lake sturgeon as common 
in the lower parts of the Cumberland and Tennessee Rivers, while Evermann (1902) says the rock sturgeon “does not appear to 
be common anywhere in the Ohio Basin.” 
