The “variability” of sperm in fish varies depending on the fertilization mode ~ It has been revealed that the length of sperm is more uniform in internally fertilized fish ~

Take Ito, Gakushin Special Researcher, Sesoko Research Facility, Tropical Biosphere Research Center, University of the Ryukyus(PD)The research results of a research team including Associate Professor Masaya Morita of the same facility, Professor Yasunori Furuya of Gifu University's Faculty of Education, Assistant Professor Seiya Okuno of Osaka Public University Graduate School of Science, and Professor Satoshi Awada have been published in the international academic journal "Journal of Evolutionary Biology” was published in the magazine.

◆Results: Marine fish11Comparing species, they found that in species that fertilize internally, there is less variation in sperm length between males and between sperm from the same male than in species that fertilize externally.

◆Novelty: In addition to differences between species, as well as the average shape and size of sperm, the research is novel in that it focuses on variations between male individuals of the same species and between sperm produced by the same male, and shows the relationship with fertilization mode and sperm competition.

◆Social significance: This will provide clues to understanding the evolutionary selection that affects spermatogenesis and the quality control mechanism of sperm itself, and is expected to lead to research that elucidates the reproductive strategies and diversification of reproductive traits in fish.