Molly A. Webb
Christopher S. Guy
Todd M. Koel
Michelle A. Briggs
2026
<p><span>Yellowstone cutthroat trout </span><i>Oncorhynchus virginalis bouvieri</i><span> in Yellowstone Lake are the focus of intensive conservation efforts due to the threat of predation by invasive lake trout </span><i>Salvelinus namaycush</i><span>. Suppression gillnetting has reduced the abundance of predatory lake trout, and the Yellowstone cutthroat trout population is recovering. Long-term monitoring indicates the size structure of the population shifted following lake trout invasion, suggesting that reproductive demographic rates of Yellowstone cutthroat trout may have changed. Length at 50% probability of maturity, as assessed using histological analysis of gonadal tissue, was 479 mm (95% confidence interval [CI] 467–490 mm) for females and 406 mm (95% CI 386–430 mm) for males, compared to 330 mm for males and females historically. Currently, age at 50% probability of maturity is 6.6 for females and 5.4 for males. The rate of skipped spawning was 3% for females and 38% for males. Mean absolute fecundity was 2897 ovarian follicles/individual at present compared to 1141 ovarian follicles/individual before lake trout invasion. Mean relative fecundity was 2157 ovarian follicles/kg. This research illustrates the plasticity in the reproductive strategies of fishes as a result of an invasive species. Understanding the reproductive biology of fish populations is vital for effective fisheries management, and these results are integral to a population model that can be used to develop new conservation benchmarks for Yellowstone cutthroat trout.</span></p>
application/pdf
10.1111/jfb.70281
en
Wiley
Plasticity in the reproductive biology of Yellowstone cutthroat trout <i>Oncorhynchus virginalis bouvieri</i> in Yellowstone Lake following lake trout <i>Salvelinus namaycush</i> invasion
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