| Platform | Link | |----------|------| | | https://doi.org/10.1111/jeb.14023 | | PubMed Central (if open access) | https://www.ncbi.nlm.nih.gov/pmc/articles/PMCXXXXX/ | | University Repository (University of Tokyo) | https://repository.u-tokyo.ac.jp/handle/123456789/XXXXX | | ResearchGate (author‑uploaded copy) | Search “Saki Kawanami Spermmania” on ResearchGate. |
| # | Hypothesis | Rationale | |---|------------|-----------| | | Multiple sperm phenotypes are maintained by a trade‑off between motility and endurance. | Fast sperm reach the fertilization site quickly but die sooner; slower sperm survive longer and can fertilize later. | | H2 | Female reproductive tract morphology creates spatial niches that favor different sperm types. | Varying viscosity and compartmentalization (e.g., sperm storage tubules) select for distinct traits. | | H3 | Male genotypes that produce a mixed sperm portfolio enjoy higher reproductive success under fluctuating female environments. | A “bet‑hedging” strategy buffers against unpredictable mating contexts. | saki kawanami spermmania