STIZOSTEDION AMERICAN PIKE-PERCHES 273 



to 5.9; eye 4.6 to 6; nose 3.S to 3.8; mouth large, terminal, little 

 oblique, maxillary past back of pupil, 2.2 to 2.4 in head; lower jaw 

 sUghtly shorter than upper; gill-rakcrs slender; pyloric caeca 3, subequal, 

 as long as stomach. Dorsal XIII or XIV, 19 to 22; longest dorsal 

 spine about 21 in head; caudal lunate; anal II, 12-14; ventrals half-way 

 to vent; pectorals 1.8 to 2.1 in head. Scales 12-14, 80-89, 19-25; 

 lateral line usually complete, some pores occasionally extending on 

 caudal fin; scales on cheeks as a rule sparse. 



Although taken by us but thirty-nine times from sixteen locali- 

 ties, and rare except in a few favorable situations where the water is 

 clear and the current swift, this species is generally distributed in 

 Illinois. It is a far-ranging species, of predominant northern dis- 

 tribution, occurring from Hudson Bay and the Saskatchewan River 

 through New Brunswick and New England to the Potomac and 

 north Georgia, and westward through all the Great Lakes and the 

 Ohio basin to Alabama and Minnesota. It is preferably, however, 

 a lake fish, and is most abundant in the Great Lakes, particularly in 

 Lake Erie. 



It is essentially a piscivorous fish, but also feeds, according to 

 Jordan and Evermann, upon crawfishes when in shallow water. Ten 

 specimens examined by us had eaten nothing but fishes, half of them 

 the hickory-shad (Dorosoma). Minnows and sunfishes were also 

 noticed. From a single wall-eyed pike caught in Peoria Lake, ten 

 specimens of gizzard-shad were taken, each from three to four inches 

 long. As this is a very thin, high fish, with a serrate belly, these 

 were about as large as a wall-eyed pike can easily swallow, and we 

 may, by a very moderate estimate of its requirements, conclude that at 

 least six hundred fishes of this size would be required for its main- 

 tenance during one year. Reckoning the average life of a pike at 

 three years, the smallest reasonable estimate of food for each pike- 

 perch would fall somewhere between eighteen hundred and three 

 thousand fishes, and a hundred pike-perch such as should each year 

 be taken along a few miles of a river like the Illinois would require 

 180,000 to 300,000 fishes for their food. Probably no fish in our 

 streams is able to meet so tremendous a demand except the hickory- 

 shad — so abundant in the food of this pike — unless the European 

 carp, generally introduced since these observations were made, may 

 be an equally acceptable victim. The wall-eyed pike is a swift and 

 vigorous swimmer, capable of overtaking a black bass. 



It reaches a maximum length of about three feet, and a weight 

 of twenty-five pounds, but examples of this size are very rare. 

 According to Jordan and Evermann, it probably does not aver- 

 age more than ten pounds in the Great Lakes. It prefers clear 



