March, 1963 Larimore & Smith: Fishes of Champaign County 



341 



Table 14. — Average number of species per station and average number and weight of fish 

 taken per 100 square yards in 1928 and 1959 at 71 stations (not noticeably affected by pollution) 

 classified bv size of drainage basin; also, average number of pounds of fish per 100 square vards 

 in 1959. 



♦Classification used by Thompson & Hunt (1930). In our work, we considered the numerals as designating size 

 limits, so that a stream classified as size 4-8 had a drainage area of more than 4 and not more than 8 square miles. 



units of stream size treated by Thompson Number of Species and Stream 



& Hunt; hence, our first point represents Size. — The number of species of fishes 



stations having 2—8 square miles of drain- per collection increases downstream. This 



age, not 0.5 — 1- miles as in the treatment hypothesis of Thompson & Hunt was sup- 



by Thompson & Hunt. 



ported by our collections in 1959. Our 



22 _ 



I8_ 



c 

 o 



o 



0) 



Q. 



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 a> 



o 14 



0) 

 Q. 



35 10 



E 



■3 



Number of Stations Represented 

 -»>l-«— 13— ►!••— 10— ►!••— 17 — ►!-< 25- 



8 16 32 64 128 256 



Drainage Area in Squore Miles 



-►I 



512 



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 XJ 



k- 



CT 

 CO 



O 



o 



_2 



Q. 



w 

 ■o 



c 



3 



g> 



Fig. 13. — Relationships of weight, number of individuals, and number of species to size of 

 the drainage area. Data for collections from the two smallest and the three largest areas of 

 stream size, table 14, were combined, as explained in the text under Relationships With Stream 

 Size on page 340. 



