Fertilization dynamics in sockeye salmon and a comparison of sperm from alternative male phenotypes

Authors

  • D. J. Hoysak,

    1. University of British Columbia, Department of Zoology, 6270 University Boulevard, Vancouver, B.C. V6T 1Z4, Canada
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  • N. R. Liley

    Corresponding author
    1. University of British Columbia, Department of Zoology, 6270 University Boulevard, Vancouver, B.C. V6T 1Z4, Canada
      Author to whom correspondence should be addressed. Tel.: +1 604 822 3224; fax: +604 822 3214; email: liley@zoology.ubc.ca
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Author to whom correspondence should be addressed. Tel.: +1 604 822 3224; fax: +604 822 3214; email: liley@zoology.ubc.ca

Abstract

Sockeye salmon Oncorhynchus nerka sperm maintained high fertility for 10 s after being exposed to water but fertility dropped sharply after that. Eggs also showed limited longevity after being immersed in water, with a large drop in fertility occurring after 20 s of exposure to water. The association between eggs and sperm occurs very rapidly. 80% fertilization success was achieved with 5 s of sperm-egg mixing and c. 25% was achieved with <0·5 s of sperm-egg mixing. Sperm from different male age classes differed little in motility and did not differ at all in their propensity to fertilize eggs. The results have important implications for mate choice and sperm competition.

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