Mating plug

<p>A mating plug, also known as a copulation plug, vaginal plug, sperm plug, or sphragis , is a gelatinous secretion used in the <a href="/facts/Mating/o2voslGF">mating</a> of some species. It is deposited by a male into a female genital tract, such as the vagina, and later hardens into a plug or glues the tract together. While females can expel the plugs afterwards, the male's sperm still gets a time advantage in getting to the egg, which is often the deciding factor in fertilization.
</p><p>The mating plug plays an important role in <a href="/facts/Sperm_competition/aKPHesdA">sperm competition</a> and may serve as an alternative and more advantageous strategy to active mate guarding. In some species, such a passive mate-guarding strategy may reduce selection on large male size. Such a strategy may be advantageous because it would allow a male to increase <a href="/facts/Reproductive_success/BjHIUg2l">reproductive success</a> by spending more time pursuing new female mates rather than active mate guarding.
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Mating plug open-in-new

Mating plug