was used by Starrett (1972) in a summary assessment of changes that had 

 occurred in fish populations of the Illinois River: 



"During the past hundred years 121 species of fishes 

 have been collected from the Illinois River and its 

 bottomland lakes (Starrett and Smith, unpublished). 

 Between 1957 and 1970 we took 101 species, nine of 

 which had not been taken in the period before 1908 

 (including two species not recognized in 1908 and 

 three exotic species) . Twenty species of fishes 

 were extirpated from the river between 1908 and 1970. 

 Several of the extirpated species were considered 

 rare or accidental species in the river. On the 

 other hand, many species of fishes common in the 

 river before 1908, including the walleye 

 ( Stizostedion vitreum vitreum ) and northern pike 

 ( Esox lucius ) , now are rare or limited in their 

 distribution. The changes which have occurred in 

 the fish fauna of the Illinois River reflect some 

 of the drastic effects modern man has had on the 

 ecology of the river."* 



The fish species extirpated from the river between 1908 and 1970 are 

 listed on Table 4. The impacts of both natural environmental changes 

 and man-made changes on the fishes of the Illinois River are discussed 

 in Part IV. 



Detailed electrof ishing results are given in Tables 5 through 29, 

 and are summarized below by species, in phylogenetic order. Not all 

 the 67 species listed in Table 3 are discussed below because the sam- 

 pling technique was not appropriate for these species and because they 

 occurred in a few collections by chance, as when small fish happened to 

 be retained in the dip nets, as a result of the %-in. mesh nets becoming 

 plugged with leaves. Tables are not presented for species represented 

 by only a few individuals from the entire river. 



* An error was probably made in totaling the number of species in 1970. 

 A total of 100 species had been obtained from 1957 through 1970. A 

 species believed extirpated by 1970, the longear sunfish ( Lepomis 

 megalotis ) , was taken in the 1973 electrof ishing survey, making the 

 total 101, as of 1974. 



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