Mating plugs occluding the female gonopore after mating are a widespread phenomenon. In scorpions, two main types of mating plugs are found: sclerotized mating plugs being parts of the spermatophore that break off during mating, and gel-like mating plugs being gelatinous fluids that harden in the female genital tract. In this study, the gel-like mating plug of Euscorpius italicus was investigated with respect to its composition, fine structure, and changes over time. Sperm forms the major component of the mating plug, a phenomenon previously unknown in arachnids. Three parts of the mating plug can be distinguished. The part facing the outside of the female (outer part) contains sperm packages containing inactive spermatozoa. In this state, sperm is transferred. In the median part, the sperm packages get uncoiled to single spermatozoa. In the inner part, free sperm is embedded in a large amount of secretions. Fresh mating plugs are soft gelatinous, later they harden from outside toward inside. This process is completed after 3-5 days. Sperm from artificially triggered spermatophores could be activated by immersion in insect Ringer's solution indicating that the fluid condition in the females' genital tract or females' secretions causes sperm activation. Because of the male origin of the mating plug, it has likely evolved under sperm competition or sexual conflict. As females refused to remate irrespective of the presence or absence of a mating plug, females may have changed their mating behavior in the course of evolution from polyandry to monandry.
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http://dx.doi.org/10.1002/jmor.10804 | DOI Listing |
Sci Rep
January 2025
Centre for Ecology and Conservation, Faculty of Environment, Science & Economy, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, UK.
Promiscuous females reduce male reproductive control. Males can attempt to monopolise access to these females, but distractions and sneaky rivals mean extra copulations cannot always be blocked. By mating first, males can obtain a headstart in sperm competition, but this may be negated by sperm storage and cryptic female choice mechanisms.
View Article and Find Full Text PDFVet Anim Sci
December 2024
Department of Animal Science, National Chung Hsing University, Taichung, 40227, Taiwan.
R Soc Open Sci
October 2024
Insect Research Biology Institute (IRBI), UMR CNRS 7261 University of Tours, Tours 37200, France.
Curr Biol
October 2024
Faculty of Science and Medicine, University of Fribourg, Chemin du Musée 14, CH-1700 Fribourg, Switzerland. Electronic address:
Females in many species bias fertilization success and paternity after mating with multiple males. Two new studies uncover the mechanisms of this phenomenon, cryptic female choice, in Drosophila, linking it to pheromone-stimulated ejection of sperm and mating plug.
View Article and Find Full Text PDFElife
September 2024
School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea.
In birds and insects, the female uptakes sperm for a specific duration post-copulation known as the ejaculate holding period (EHP) before expelling unused sperm and the mating plug through sperm ejection. In this study, we found that females shortens the EHP when incubated with males or mated females shortly after the first mating. This phenomenon, which we termed ale-nduced HP hortening (MIES), requires Or47b+ olfactory and ppk23+ gustatory neurons, activated by 2-methyltetracosane and 7-tricosene, respectively.
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