MILXER FISHERIES OF THE GREAT LAKES. 03 



hooks sot in the lake, and in one day took from these live hnndred lizards, 

 removing- them all himself, as his men, sharing the popnlar notioij on the 

 lakes, believed them to be poisonous, and preferred to cut away hook 

 and all to taking hold of the slimy amphibian. They are, of course, en- 

 tirely harmless in this particuhir, and make no more attempt to bite than 

 a frog does. 



A full series of this species was this season collected from Detroit 

 Elver, from the length of one and one-fourth inches to thirteen inches. 

 Later, about the middle of the month of July, Mr. George Clark col- 

 lected a quantity of their eggs, proving this month to be the spawning- 

 season of the animal. 



The sturgeon are very generally believed to be spawn-eaters. Though 

 the ova of the white-fish and the perch have been observed among the 

 stomach-contents of this fish, the principal food has always been found 

 to be snails, the fresh-water genera being generally represented, the 

 weaker shells crashed into fragments, and the stronger ones of the Fa- 

 ludinidw and even Lhnneas remaining unbroken. 



Dr. E. Sterling, of Cleveland, who examined the stomachs of a large 

 number of sturgeon in the vicinity of the Sandusky fisheries, made the 

 same observation. 



There are few of the bottom-feeding fishes but whose stomachs will 

 not generally be found to contain a few eggs, though in company with 

 other food in greater quantity. 



The white-fish stomach is generally found to contain a few fish-eggs, 

 though its priucipal food is the Crustacea. The habit of leaving the shore 

 immediately after spawTiing probably pie vents it from being an agent in 

 diminisliing its o^vn numbers. 



The natural casualties of storms, deposits of sedmient, smothering the 

 eggs, the vegetable growth found to be so fatal in the hatching- troughs, 

 are to be considered in this oonnection as the dangers, though more fully 

 represented on another page. 



In the fry-stage they must suffer to some extent from the piscivorous 

 fishes. The most numerous and voracious of their enemies is likely to be 

 the wall-eyed pike, Stizostedion americana, numerous in the shoal waters 

 of the lakes and comparatively rare on the deeper shores. The perch, 

 Ferca flavescensy are very generally distributed and quite numerous; the 

 contents of their stomachs are generally found to be vertebrate forms. 

 The black-bass, Micropterns nigricans, is plentiful in Lake Erie, but as its 

 ordinary food is the craw-fish, where these are numerous its depredations 

 on the schools of young fish would be of comparatively little importance. 

 The white-bass, iioccws clinjsops, the muskellunge, Ehox nohilior, and the 

 lake-pike, Usox lucius, do not inhabit the lakes in sufficient numbers to 

 be very troublesome to the white-fishes. 



It is the prevailing idea on the lakes that the Mackinaw or salmon- 

 trout feeds largely on the white-fish. This point has been fully consid- 

 ered on a iJ.revious page, and the evidences disproving it related. 



