Individual- and ejaculate-specific sperm traits in ant males Journal Article

Author(s): Metzler, Sina; Schrempf, Alexandra; Heinze, Jürgen
Article Title: Individual- and ejaculate-specific sperm traits in ant males
Affiliation IST Austria
Abstract: Sperm cells are the most morphologically diverse cells across animal taxa. Within species, sperm and ejaculate traits have been suggested to vary with the male's competitive environment, e.g., level of sperm competition, female mating status and quality, and also with male age, body mass, physiological condition, and resource availability. Most previous studies have based their conclusions on the analysis of only one or a few ejaculates per male without investigating differences among the ejaculates of the same individual. This masks potential ejaculate-specific traits. Here, we provide data on the length, quantity, and viability of sperm ejaculated by wingless males of the ant Cardiocondyla obscurior. Males of this ant species are relatively long-lived and can mate with large numbers of female sexuals throughout their lives. We analyzed all ejaculates across the individuals' lifespan and manipulated the availability of mating partners. Our study shows that both the number and size of sperm cells transferred during copulations differ among individuals and also among ejaculates of the same male. Sperm quality does not decrease with male age, but the variation in sperm number between ejaculates indicates that males need considerable time to replenish their sperm supplies. Producing many ejaculates in a short time appears to be traded-off against male longevity rather than sperm quality.
Keywords: Cardiocondyla; mating success; reproductive physiology; sperm phenotype
Journal Title: Journal of Insect Physiology
ISSN: 00221910
Publisher: Elsevier  
Date Published: 2018-01-01
Start Page: Epub ahead of print
DOI: 10.1016/j.jinsphys.2017.12.003
Notes: Research with C. obscurior from Brazil was permitted by Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis, IBAMA (permit no. 20324-1). We thank the German Science Foundation ( DFG ) for funding ( Schr1135/2-1 ), T. Suckert for help with sperm length measurements and A.K. Huylmans for advice concerning graphs. One referee made helpful comments on the manuscript.
Open access: no