March, 1963 Larimore & Smith: Fishes of Champaign County 



333 



shown by A^. lutrensis, which entered the 

 county between 1928 and 1959. A mhlo- 

 plites rupestris and Micropterus dolornieui 

 show an irrefutable increase in abundance 

 and occurrence within Champaign Coun- 

 ty, but there is no evidence that their 

 ranges within the state have changed. 

 These species would have been benefited 

 by the increased stream gradient and 

 lower maximum water temperatures that 

 may have resulted, as suggested in the sec- 

 tion on Changes in Stream Habitats, 

 from drainage and dredging operations. 

 Similarly, Hypenteliiun nigricans, N. 

 chrysocephalus, Hybopsis biguttata, No- 

 turits flavuSj and Campostoma anomalum 

 show decided, if inexplicable, increases in 

 occurrence within the county, but their 

 over-all ranges within the state appeared 

 to be the same in 1959 as 60 years before. 



On the basis of evidence from the three 

 surveys, 15 species exhibited an equally 

 striking decrease in abundance and in 

 shrinkage of distributional pattern within 

 the county over the 60-year period of 

 study. These species, the percentage of 

 stations in which they were found, and 

 the number of drainages in which they 

 were taken at each survev are listed in 

 table 8. 



Data for the entire period covered by 

 the three surveys indicate that Ictiobus 

 bubalus. Hybopsis aestivalis, and Notropis 

 heterolepis disappeared from Champaign 

 County before 1928. A'', heterolepis, if 

 Forbes & Richardson correctly identified 

 the specimens to which they assigned this 

 name, is of particular interest because it 

 occurred in two different drainage systems 

 prior to 1899 and probably disappeared 

 with the draining of the once extensive 

 prairie marshes. /. bubalus may be ex- 

 pected to be taken again in Champaign 

 County, for it occurs in large streams only 

 a few miles outside the county. 



Hybopsis amblops, Piniephales vigilax, 

 Etheostoma chlorosomum, Notropis boops, 

 and Opsopoeodus emiliae may have de- 

 clined in numbers by 1928; they disap- 

 peared between 1929 and 1959. The re- 

 maining seven species listed in table 8 are 

 still present, but they are much less com- 

 mon than formerly. All of them except 

 Esox americanus suggest that their marked 

 decline in the county occurred between 

 1899 and 1928. One, Minytrema mela- 



nops, was described by Large (1903:12) 

 as "abundant in the Wabash basin and in 

 the headwaters of the Kaskaskia" and "ap- 

 parently prefers the weedy prairie creeks 

 in situations where it is abundant." £. 

 americanus \vas e\idently about equally 

 common in 1899 and 1928 but had de- 

 creased sharply by 1959, presumably be- 

 cause of the destruction by dredging of 

 its preferred habitat (pools with luxuriant 

 aquatic vegetation ) . 



The extirpation of six other species 

 {Ictiobus cyprinellus, I. niger, Notropis 

 amnis, Noturus exilis, Lepomis punctatus, 

 and Etheostoma gracile) from Champaign 

 County is almost certain ; they have not 

 been included in table 8 because informa- 

 tion regarding their abundance, or even 

 their presence, was unavailable prior to 

 the 1928 investigation. Of the extirpated 

 species, E. gracile, N. exilis, and Hybopsis 

 amblops are noteworthy because they 

 were, until 1928, peripheral populations 

 in the county. The northernmost record 

 in the range of E. gracile, the eastern- 

 most record in the range of A^ exilis, and 

 the westernmost record of H. amblops, at 

 least in this region, were in Champaign 

 County. Within the past 30 years, shrink- 

 age in the ranges of these three species, re- 

 spectively to the south, west, and east, 

 has occurred. This shrinkage is evident 

 over the state as a whole as well as within 

 Champaign County. 



Despite the impressive changes in 

 abundance and distribution of the species 

 discussed in the paragraphs above, it is dif- 

 ficult to describe the changes in the 

 Champaign County fish fauna as radical, 

 for roughly half of the species showed no 

 decided trends. Examination of distribu- 

 tion maps, figs. 15-70, that accompany 

 this report will reveal that the occurrence 

 of several species was remarkably similar 

 throughout the 60-year period of observa- 

 tion. Several species exhibited consider- 

 able changes in distribution but these spe- 

 cies cannot be regarded as being any more 

 or less common, or more or less widely 

 distributed, in the county in 1959 than 

 they were in 1928 or 1899. In view of 

 the great changes in land use, in the 

 stream courses, and in the stream habitats 

 that occurred in the county over a 60- 

 year period, and the catastrophic effects 

 of the several drought years since 1930, 



