Investigations into lake sturgeon reproductive effort : trade-offs between current and future reproduction
Organisms often vary resource expenditures devoted to reproduction in response to environmental conditions and to biotic conspecific and heterospecific interactions. Resource allocation decisions can also affect future reproductive effort and success. In Chapter 1, I examined how intra- and inter-sexual behavior, biotic variables, and environmental conditions affected individual investments in current year reproductive effort. Results indicated that male lake sturgeon inter-spawning interval decreased as body size (a surrogate of age) increased. In Chapter 2, I examined the role of ovarian fluid in lake sturgeon egg fertilization success and post-fertilization embryo survival when eggs are fertilized with sperm from related and unrelated males. Eggs fertilized by males not related to a female showed higher proportional egg survival than half-sibling males 72-hours following fertilization. No interaction of the unrinsed ovarian fluid and relatedness was observed, suggesting that higher egg survival associated with unrelated males was not attributed to ovarian fluid. The lack of rinsing of ovarian fluid during sperm activation resulted in reduction of sperm velocity and motility, but results were unaffected by the relatedness of the mated pair. Results demonstrated that ovarian fluid may alter sperm velocity and quality, but the reduction in survival of progeny from half-sibling matings did not result from ovarian fluid on the egg surface. Collectively, findings presented provide greater understanding of how behavioral, biological, and environmental factors affect reproduction in lake sturgeon. Studies highlight the value of long-term collection of data to inform species management. Results generated from these experiments contribute to the understanding of how long-lived species plastically respond to current environmental conditions and how effort toward reproductive success varies with age and size at the individual and to population levels.
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- In Collections
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Electronic Theses & Dissertations
- Copyright Status
- Attribution-NoDerivatives 4.0 International
- Material Type
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Theses
- Authors
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Larson, Douglas L., Jr.
- Thesis Advisors
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Scribner, Kim T.
- Committee Members
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Roth, Brian
Brenden, Travis
Baker, Edward
- Date Published
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2023
- Program of Study
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Fisheries and Wildlife - Master of Science
- Degree Level
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Masters
- Language
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English
- Pages
- 102 pages
- ISBN
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9798379501631
- Permalink
- https://doi.org/doi:10.25335/bd47-8y94