ACIPENSER- — ^THE STURGEONS 25 



and belly and of sides between scutes more or less densely covered with 

 small rough spinule- or tubercle-like ossifications;''' sides of upper 

 caudal lobe sheathed with small rhombic plates. 



This species, which is confined to inland waters, was formerly 

 abundant throughout the Great Lake region and the Mississippi 

 Valley. Lake sturgeon have of late years been steadily decreasing, 

 and are now only rarely taken in the Mississippi on our own borders, 

 and are seldom caught in the Illinois. Fishermen at Alton now see 

 but five or six in a year that weigh over 10 fb, whereas fifteen years 

 ago forty or fifty large ones, weighing from 50 to 100 tb, were taken 

 each season. 



The lake sturgeon is said to inhabit comparatively shoal waters 

 in the lakes, ascending streams in the spring to spawn. The most 

 extensive study of their habits has been made by Milner, who found 

 their food, in the Great Lakes, to consist almost entirely of fresh- 

 water snails {Gasteropoda). Crawfishes and insect larvae are 

 also eaten by them, and the eggs of fishes have been occasionally 

 found in their stomachs, though not in quantity sufficient to justify 

 the charge of destructive spawn-eating sometimes made. Lake 

 sturgeon taken in the vicinity of grain elevators have been found 

 with stomachs well filled with corn or wheat. They spawn early in 

 June, generally preferring rocky ledges near the shores. While their 

 spawn is probably subject to the depredations of other fishes, the 

 young are w^ell protected, after reaching two or three inches in 

 length, by their spine-tipped bucklers Adult sturgeons are much 

 subject to attack by lampreys. 



Previous to 1870 the flesh of the lake sturgeon was scarcely used. 

 Fishermen generally made no use of them at all, and by many they 

 were considered a nuisance and ruthlessly destroyed. In the 

 following decade, however, several firms began the business of 

 smoking lake sturgeon and manufacturing caviar, isinglass, and oil 

 from the eggs, air-bladders, and viscera. Smoked lake sturgeon is 

 now considered a superior article, and lake caviar is ranked as the 

 best produced in the United States — selling (in 1898) for eighty 

 cents a pound, while the Delaware product brought only sixty cents, 

 and the South Atlantic fifty cents (Gill). 



The artificial propagation of lake sturgeon was seriously con- 

 sidered by the United States Government in 1898, w^hen a hatchery 



* Younger specimens are much rougher than adults; in a young sturgeon 10 

 inches long taken at Ottawa, 111., each lateral scute has a peculiar flexuose keel or 

 ridge in place of the characteristic central spine, and the ventral plates are similarly 

 keeled. We have small specimens in addition which are perfectly normal in the 

 character mentioned. 



