96 NORTHERN FISHES 



GENUS Leiicichthys Dybowski 



Members of this genus are characterized by two flaps between the 

 openings of each nostril and by the terminal mouth. Usually more than 

 .SO rather long and fine gill-rakers are present on the first branchial 

 arch. Vestigial teeth may be present on the premaxillaries, palatines, 

 mandible, and tongue. The premaxillaries are longer than they are 

 wide. The mandible is seldom contained more than 3.1 times in the 

 head. The males develop pearl organs on the head and sides during 

 the spawning season. 



This genus includes the common lake cisco, or herring, and the re- 

 lated tullibee of inland lakes, and the chubs, ciscoes, and bluefins of 

 Lake Superior and other Great Lakes. For some species distinct sub- 

 species have developed in different ones of the Great Lakes, and in some 

 of the Great Lakes some species are found that are not present in the 

 others. The species treated here include only those found in Lake 

 Superior. 



In various places local fishermen have applied the common names "cis- 

 co" and "tullibee" indiscriminately to different species of Leiicichthys. 

 Members of the genus are common in many of the northern lakes of 

 America. Closely related species placed in the genus Coregonus are 

 found in northern Europe and Asia. 



LAKE SUPERIOR CISCO (Lake Herring, Blueback) 

 Leucichthys artedi arcturus Jordan and Evermann 



The Lake Superior cisco, or herring,* is large, reaching a length of 12 

 inches or more. The body shape is subterete or elongate. The lower jaw 

 is either equal to or slightly shorter than the upper. There are usually 

 more than 43 gill-rakers. The lateral-line scales seldom number less than 

 80. Frequently confused with the common whitefish, the Lake Superior 

 cisco can be readily distinguished by the absence of the overhanging 

 snout and upper jaw characteristic of the whitefish and some other 

 coregonids (Diagram 4) . 



This species is the most abundant member of the family Coregonidae 

 found in the Minnesota waters of Lake Superior. The slender variety, L. 

 artedi arcturus, is more common than the deeper and more compressed 

 form, L. artedi albus (LeSueur) . Other subspecies occur in the other 

 Great Lakes. Ciscoes often run in schools and are commonly caught in 

 gill and pound nets. They are pelagic, usually staying near the surface 

 in deep, open water, where they swim down to a depth of several 

 hundred feet. They feed largely on planktonic crustacea and occasion- 

 ally on insects. 



In late July and early August they migrate close to shore in Lake 



*The name "herring" is a misnomer, for these fishes are in no way related to the true 

 herring family. 



