Substrate 



Cobble appeared to be the preferred substrate for the two sculpin 

 species, although there were variations in the percentage of 

 cobble versus other substrate sizes (Figure 5) . Sites with 

 abundant sculpin populations typically were dominated by cobble 

 substrate. There was a corresponding decline in sculpin 

 abundance at sites where substrate particle size shifted to the 

 gravel and sand size class. It appeared that torrent sculpin 

 were more tolerant of mixed substrate containing some degree of 

 gravel and sand. Sculpin were not present in reaches which did 

 not contain at least some degree of cobble substrate. 



Temperature 



Temperature was recorded at random times of the day while 

 electroshocking. As a result, comparisons of species specific 

 stream temperatures using statistical analysis were not 

 appropriate. However, temperature trends were distinguishable 

 for each species except at sites where species were rare in 

 occurrence (Figure 6) . 



Torrent sculpin tended to be found at sites with warmer stream 

 temperatures than those occupied by slimy sculpin. The observed 

 mean temperature at sites containing torrent sculpin was 59. 8 "F. 

 This was 3.9°F degrees higher than the observed mean temperature 

 at sites containing slimy sculpin. The observed mean temperature 

 where torrent and slimy sculpin were abundant was 68.0°F and 

 54.8°F respectively. 



The warmest temperatures recorded at a site with torrents was 

 7 0.0°F and with slimies was 67.0°F. However, torrents were 

 abundant, while slimies were rare at these sites. 



13 



