CR1STIVOMER GEEAT LAKE TROUT 55 



generally known by the much more distinctive name of cisco, 

 already frequently used for it but now commonly limited to a 

 variety of the species found in the smaller lakes of Wisconsin 

 and of Indiana, but not in those of Illinois. 



In food and habits it is similar to the common whitefish, 

 although it is notorious for its enormous destruction of the 

 spawn of the latter, upon whose multiplication, in view of its 

 own greater abundance and the rapidly decreasing supply of 

 whitefish, it must place a serious check. Like the whitefish it 

 spends the summer and the winter in the deeper water of its 

 habitat, moving shorewards in spring evidently in search of 

 food, and again in fall for the deposit of its spawn, which takes 

 place chiefly in November. Its eggs are laid in shallow water/ 

 preferably upon a sandy bottom, although it sometimes spawns 

 on the mud along the borders of the shallower waters of the 

 lakes and in the mouths of their tributary streams. 



It is caught with gill-nets in shallow water from April to 

 the last of May, but the larger part of the catch is obtained by 

 pound-nets. Up to 1899 it seems to have withstood successfully 

 the enormous drain of our fisheries, the yield of that year being 

 more than double that of 1885, while the catch of whitefish, on 

 the other hand, had diminished to less than a third. 



In addition to the common lake herring, four other species 

 of the genus Argyrosomus (A. hoyi, the mooneye cisco; A. 

 prognathus, the longjaw; A. nigripinnis, the bluefin; and A. 

 tullibee, the tullibee) are more or less commonly taken in Lake 

 Michigan. None of these species is as abundant as the lake 

 herring (A. artedi), however, and none, unless the bluefin, is 

 taken at all frequently in southern Lake Michigan, within the 

 limits of this state. For purposes of the present report all of 

 these species are sufficiently characterized in the key to the 

 species of Argyrosomus preceding. 



GENUS CRISTIVOMER GILL & JORDAN 



GREAT LAKE TROUT 



Body moderately elongate; mouth large; hyoid with a band of strong 

 teeth; vomer boat-shaped, with a raised crest behind the head and free from 

 its shaft, this crest being armed with teeth; caudal little forked; scales very 

 small. 



