Confirmation of Species Identity and Age Estimation of Pygmy Whitefish from Sullivan Lake WA.
Faculty Mentor
Paul Spruell
Presentation Type
Poster
Start Date
4-14-2026 9:00 AM
End Date
4-14-2026 11:00 AM
Location
PUB NCR
Primary Discipline of Presentation
Biology
Abstract
Pygmy Whitefish (Prosopium coulterii) are native to Washington and distributed across nine lakes statewide. Seven of these lakes are east of the Cascade Range, including Sullivan Lake. The population status of Pygmy Whitefish in Sullivan Lake is unknown. We confirmed species identity and documented age distribution and condition factors for the Sullivan Lake population. A total of sixty-seven samples were collected from the lake during the summer of 2025. Species determination was done using DNA barcoding of the 5′ region of the mitochondrial cytochrome c oxidase I (COI) gene. DNA was extracted using QIAGEN DNeasy Blood and Tissue extraction kits, then sequenced by GENEWIZ Laboratories. We confirmed species identity by uploading sequences to the NCBI BLAST database. Age estimation was done using back-calculations of length, length-frequency histograms, and counting the number of annuli on scales and otoliths. Analysis of length-frequency histograms revealed expected age classes between zero and four years. A preliminary sample of 18 fish were estimated to be between 1+ and 4+ years old. Average back calculated lengths (±SD) at ages one through four were: 59.61 ± 4.83, 96.38 ± 8.15, 118.90 ± 4.28, and 154.67 ± 11.5 millimeters. Condition factor (K) displayed strong seasonal variation, with mean K increasing from 0.268 (SD = 0.067) for fish sampled in June to 0.696 (SD = 0.077) for fish sampled in September. Collectively, these results provide background information on the population status and condition metrics of Pygmy Whitefish in Sullivan Lake.
Recommended Citation
Greene, James, "Confirmation of Species Identity and Age Estimation of Pygmy Whitefish from Sullivan Lake WA." (2026). 2026 Symposium. 22.
https://dc.ewu.edu/srcw_2026/ps_2026/p1_2026/22
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Confirmation of Species Identity and Age Estimation of Pygmy Whitefish from Sullivan Lake WA.
PUB NCR
Pygmy Whitefish (Prosopium coulterii) are native to Washington and distributed across nine lakes statewide. Seven of these lakes are east of the Cascade Range, including Sullivan Lake. The population status of Pygmy Whitefish in Sullivan Lake is unknown. We confirmed species identity and documented age distribution and condition factors for the Sullivan Lake population. A total of sixty-seven samples were collected from the lake during the summer of 2025. Species determination was done using DNA barcoding of the 5′ region of the mitochondrial cytochrome c oxidase I (COI) gene. DNA was extracted using QIAGEN DNeasy Blood and Tissue extraction kits, then sequenced by GENEWIZ Laboratories. We confirmed species identity by uploading sequences to the NCBI BLAST database. Age estimation was done using back-calculations of length, length-frequency histograms, and counting the number of annuli on scales and otoliths. Analysis of length-frequency histograms revealed expected age classes between zero and four years. A preliminary sample of 18 fish were estimated to be between 1+ and 4+ years old. Average back calculated lengths (±SD) at ages one through four were: 59.61 ± 4.83, 96.38 ± 8.15, 118.90 ± 4.28, and 154.67 ± 11.5 millimeters. Condition factor (K) displayed strong seasonal variation, with mean K increasing from 0.268 (SD = 0.067) for fish sampled in June to 0.696 (SD = 0.077) for fish sampled in September. Collectively, these results provide background information on the population status and condition metrics of Pygmy Whitefish in Sullivan Lake.
