Bluegill (Lepomis macrochirus) 



The largest number and most pounds of bluegill per 30 minutes of 

 electrofishing were taken in 1974 (Table 25) . Bluegill populations 

 generally increased in the downstream direction, with either Alton or 

 LaGrange Pools having the greatest number and most pounds. However, 

 more were taken in Marseilles Pool than in the next pool downstream, 

 Starved Rock; only in 1969 were more bluegill obtained in Starved Rock 

 than in Marseilles. 

 Longear sunfish (Lepomis megalotis) 



One species, the longear sunfish ( Lepomis megalotis ) , believed by 

 Starrett and Smith (Starrett, 1972) to have been extirpated from the 

 Illinois River and its bottomland lakes between 1908 and 1970, was taken 

 from LaGrange Pool, Turkey Island Chute (mile 147.3-148.2) on 

 September 5, 1973. Three adults, ranging in total length from 4.2 to 

 6.1 in., were taken. 



One of these fish was preserved and later examined by Dr. Phillip W. 

 Smith, Taxonomist, Illinois Natural History Survey, who assigned it to 

 the subspecies known as the central longear sunfish ( Lepomis megalotis 

 megalotis ) . A subspecies known as the northern longear sunfish ( Lepomis 

 megalotis peltastes ) occurs in northern tributaries of the Illinois 

 River, but has not been taken from the Illinois. 

 Smallmouth bass (Micropterus dolomieui) 



The few smallmouth bass ( Micropterus dolomieui ) were probably in- 

 troduced from tributary streams that are smaller and colder than the 

 Illinois River. Thirty-two smallmouth were taken from 1959 to 1974: 

 two from Marseilles Pool, one from Starved Rock Pool, and 29 from Peoria 

 Pool. 

 Largemouth bass (Micropterus salmoides) 



The largemouth bass is a game species. Largemouth populations 

 generally increase in the river in a downstream direction. However, 

 fewer bass were taken at the two stations in Starved Rock Pool than 

 in the three stations in the next pool upstream, Marseilles Pool 

 (Table 26). Bass populations in the river were high in 1960 and 1961, 



33 



