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Within-population variation in ejaculate characteristics in a prolonged breeder, Peron's tree frog, Litoria peronii


Sherman, CDH and Uller, T and Wapstra, E and Olsson, M, Within-population variation in ejaculate characteristics in a prolonged breeder, Peron's tree frog, Litoria peronii, Naturwissenschaften, 95, (11) pp. 1055-1061. ISSN 0028-1042 (2008) [Refereed Article]

DOI: doi:10.1007/s00114-008-0423-7


Sperm number is often a good predictor of success in sperm competition; however, it has become increasingly clear that, for some species, variation in probability of paternity cannot be explained by sperm number alone. Intraspecific variation in ejaculate characteristics, such as the number of viable sperm and sperm longevity, may play an equally important role in determining fertilization success. Here, we assess variation among ejaculates in three factors that may contribute to fertilization success (number of sperm per ejaculate, viability, and longevity), in a population of Peron's tree frog (Litoria peronii). We detected large variation among males in the number of sperm per ejaculate and the proportion of viable sperm within ejaculates, which could not be explained by variation in either male size or body condition. However, the proportion of viable sperm released by males increased over the season. Finally, we assessed sperm longevity (proportion viable sperm determined using a dual-fluorochrome vital dye) at two different temperatures. At 23°C, on average, 75% of sperm remained viable after 2 h, but there were significant differences amongst males with the percentage of viable sperm ranging from 43% to 95%. For sperm incubated at 4°C, ejaculates varied fivefold in sperm longevity with some males having 50% viable sperm after 5 days. Our data suggest that ejaculate characteristics (sperm number, viability, and longevity) vary widely in Peron's tree frog and may therefore play an important role in determining siring success both in the presence and absence of sperm competition. We discuss the results in relation to selection on ejaculate traits via natural and sexual selection in this and other amphibians. © 2008 Springer-Verlag.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Ecological physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the biological sciences
UTAS Author:Wapstra, E (Associate Professor Erik Wapstra)
ID Code:53647
Year Published:2008
Web of Science® Times Cited:19
Deposited By:Zoology
Deposited On:2008-12-19
Last Modified:2011-11-22

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