Distribution and Habitat Use of Cottids in the Lake Washington Basin

摘要

We collected cottids Cottus spp. from a wide variety of habitat types in the Lake Washington basin to determine their distribution and habitat use. Habitat types included large lowland lakes, riverine habitats, and off-channel ponds. Cottids were alsocollected above and below anadromous barriers on the Cedar River, the main tributary to Lake Washington. In general, the five species of cottids in the Lake Washington basin appeared to be spatially segregated. Prickly sculpin Cottus asperwas the dominant cottid species in benthic areas of the lowland lakes. Coastrange sculpin C. alecticus primarily inhabited riffles in the lower reaches of riverine systems, but they were also found along the shoreline of Lake Washington. Riffle sculpin C. gulosus weretypically found in low-velocity areas in the lower Cedar River and Issaquah Creek and were the dominant species in off-channel habitats. Torrent sculpin C. rhotheus occupied a wide range of habitats and appeared to be the most numerous cottid in the lower Cedar River and Bear Creek (a Sammamish River tributary). When sympatric with other cottids, shorthead sculpin C, confusus appeared to primarily inhabit riffles; however, they appeared to occupy a wide range of habitats when allopatric (above anadromous barriers).