34 



sculpins in sympatry. Additional sites may have contained shortheads also but the 

 specimens could have been mistakenly identified as slimys in die field and returned to the 

 stream. 



Geologic factors may possibly account for the limited distribution of shorthead 

 sculpins. The shorthead sculpin populadon in the St. Regis River basin could be a remnant 

 population which previously had a wider distribution. Geologic events leading up to and 

 after the release of Glacial Lake Missoula could have effected the distribution of shortheads 

 in the study area (Doug Perkinson, personal communication). 



Shorthead sculpins appear to be the only sculpin species present in the St. Regis River 

 watershed. Physical, chemical, and biological factors in the St. Regis watershed may be 

 advantageous for shorthead sculpins enabling them to competitively exclude other sculpin 

 species. Shorthead sculpins may have had a much larger distribution and density in die 

 study area at one time. In fact, the four sites containing shorthead sculpins in sympatry 

 with slimy sculpins could be indicative of part of the former distribution of this species. 



Recent genetic work on sculpins serves to compound die confusion over shorthead 

 distribution even more. This research suggests diat distinguishing between motded 

 sculpins (Cottus bairdi) and shorthead sculpins in the Columbia River Basin might be 

 questionable since it is suspected that die two species hybridize (Dr. William Gould, 

 personal communication). Therefore, laboratory identificadons suggesting an addidonal 

 four shorthead sculpin locations outside the St. Regis River watershed could actually be 

 distributional data points for mottled sculpins. 



Sympatry between torrent and slimy sculpins appeared to be present at only two sites. 

 Sympatry may be more common between torrent and slimy sculpins than was found in this 

 study. Species specific habitat preferences were not distinguishable. Sites in close 

 proximity to the main Kootenai River appeared to provide suitable slimy habitat as 



