species collected at a single site was 20 from Detweiller Marina (RM 170.7) in 

 Peoria Reach. The fewest species collected at a single site was eight from Bulls 

 Island (RM 240.7) in Starved Rock Reach. Of the 41 species and 2 hybrid crosses^ 

 10 species and one hybrid cross were collected at only a single site, and five 

 species were collected at only two sites. Seven species and one hybrid cross were 

 represented by single individuals, and only two individuals were collected for each of 

 seven species. 



From 26 sites on the Illinois Waten,vay, v^'e collected 5,009 fish representing 

 41 species (plus two hybrids) from 1 1 families during 23.75 h of sampling At 

 Brickhouse Slough on the Mississippi River (RM 204.9), we collected 53 fish 

 representing 12 species from seven families (Table 2) This year's sample from 

 Brickhouse Slough provided fewer fish and relatively low diversity compared with 

 other samples collected at this site since 1991 (see Lerczak et al. 1994:49, 1995:9, 

 1996:8). 



On the lower Illinois River, v/e collected 578 fish representing 23 species 

 (Table 2). The total abundance and species richness were slightly lower than 

 observed in 1995, when 751 fish representing 25 species v^ere collected (Lerczak et 

 al. 1996:8) In 1996, species richness ranged from 14 at Mortland Island (RM 18.8). 

 Dark Chute (RM 25.0), and Hurricane Island (RM 27.5) to 15 at Crater-Willow 

 Islands (RM 30.0) and Big Blue Island (RM 58.5). The species richness at Dark 

 Chute was greater than observed in recent years; only 1 1 species were collected in 

 1 994. and 1 3 were collected in 1 995 However, in 1 996 fewer species were 



