Hackett, Travis R., author2024-12-162024-12-162024https://hdl.handle.net/10217/239712Colorado State University Honors Program - Fall 2024.We characterized length-at-age relationships of mottled sculpin (Cottus bairdii) in the Lower Blue River, a regulated high-elevation river in the southern Rocky Mountain region, Colorado, USA. Sculpin were collected in May, August, and October in a dry year and a wet year, and sagittal otoliths were sectioned for age estimation. Age-1 fish grew rapidly followed by slowed annual growth and a relatively long life span, with the oldest individual inferred to be 9 years old at 119 mm in total length. These patterns might be due to the altered flow regime characterized by hypolimnetic dam water release, resulting in suboptimal summer water temperatures for growth, oligotrophic conditions, and low abundance of prey resources. When comparing length at age between mottled sculpin found in the Blue River and other Cottidae in separate systems, we found that mottled sculpin in the Blue River have much more rapid early life growth compared to other cottids. Our study reports length-at-age relationships of a small-bodied species in an anthropogenically altered river, and additional research is warranted to compare their life history characteristics over space and time.born digitalStudent worksengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.mottled sculpinlength-at-agehigh-elevationotolithsText