70- 



60- 



i 



tn 50- 



fe 40H 

 £5 30 



CD 



I 20-) 



z 



EL0K0MIN 

 N = 202 

 P= 39 



IOH 

 



_□ 



IE 



HERMAN CR. 

 N = 31 

 P = 4 



oooogooo 

 io£cocn2 = ~9 



inior^cScnQz:™ 



o o o o 



ID t^- 00 (T) 



■ 111 



if) ID I s - 00 



LENGTH (MM.) 



Figure 3.— Length frequencies of reticulate sculpin col- 

 lected after releases of salmon in the Elokomin River 

 in 1962 and 1963 and in Herman Creek in 1962. 

 Salmon predators are shaded, and nonpredators are 

 unshaded. N = total number of sculpins in sample 

 of which P = number of predators. Total number of 

 sculpins is smaller than in Table 4 because Table 4 

 includes some sculpins taken above the release site 

 and prior to the release of hatchery reared salmon. 



specific differences in mouth size of sculpins. 

 Populations were examined from the Elokomin 

 River (prickly, coastrange, reticulate, and tor- 

 rent sculpins), Herman Creek (prickly and re- 

 ticulate sculpin), and Abernathy Creek (a 

 stream near the Elokomin River with the same 

 composition of sculpins). Chi-square tests of 

 the D 2 statistics showed that prickly, reticulate, 

 and torrent sculpins are not separable on the 

 basis of mouth size — but suggested that the 

 coastrange sculpin has a smaller mouth than 

 the other sculpins. Thus, the low intensity of 

 predation by coastrange sculpins on salmon 

 may be explained in part by the smaller mouths. 



Figure 4.-Length frequencies of torrent sculpin collected 

 after releases of salmon in the Elokomin River in 

 1962 and 1963. Salmon predators are shaded, and 

 nonpredators are unshaded. N = total number of 

 sculpins of which P = number of predators. Total 

 number of sculpins is smaller than in Table 5 because 

 Table 5 includes some sculpins taken above the release 

 site and prior to the release of hatchery reared salmon. 



