Sperm morphology, swimming velocity, and longevity in the house sparrow Passer domesticus
2010 (English)In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 64, no 4, 557-565 p.Article in journal (Refereed) Published
Sperm competition exerts strong selection on males to produce spermatozoa with an optimal morphology that maximizes their fertilization success. Long sperm were first suggested to be favored because they should swim faster. However, studies that investigated the relationship between spermlength and sperm competitive ability or sperm swimming velocity yielded contradictory results. More recently, ratios of the different sections of a spermatozoon (the head,midpiece, and flagellum)were suggested to bemore crucial in determining swimming velocity. Additionally, sperm ability to remain and survive in the female storage organs may also influence fertilization success, so that optimal sperm morphology may rather maximize sperm longevity than velocity. In this study, we investigated how sperm morphology is related to sperm velocity and sperm longevity in the house sparrow Passer domesticus. Sperm velocity was found to be correlated with head/flagellum ratio. Sperm with small heads relative to their flagellum showed higher swimming velocity. Additionally, shorter sperm were found to live longer. Finally, we found sperm morphological traits to vary substantially within males and the head/flagellum ratio to be unrelated to total sperm length. We discuss the hypothesis that the substantial within-male variation in sperm morphology reflects a male strategy to produce a diversity of sperm from long, fast-swimming to short, long-living sperm to maximize their fertilization success in a context of sperm competition.
Place, publisher, year, edition, pages
2010. Vol. 64, no 4, 557-565 p.
passer domesticus, sperm competition, sperm flagellum, sperm length, sperm longevity, sperm midpiece, sperm morphology, sperm velocity
IdentifiersURN: urn:nbn:se:uu:diva-261079DOI: 10.1007/s00265-009-0871-xOAI: oai:DiVA.org:uu-261079DiVA: diva2:849600