Scientists at the Smithsonian and their colleagues have
discovered a new mechanism of animal mating plug production. In
the giant wood spider Nephila pilipes, a highly sexually
dimorphic and polygamous species, many small males compete with
one other for access to a few huge females. During copulation
these males are known to sever their own genitals in an attempt
to plug the female, thereby gaining paternity advantage by
preventing other males from mating with her. Until recently
however, nothing has been known about the origin and function of
additional and very solid plugs researchers have observed that
also commonly cover female genitals in this species. Now
biologists have discovered the origin of this additional other
plugging mechanism. The international team of scientists who
published their findings in the July 19 issue of the journal
PLoS ONE, consists of Matja Kuntner, research associate at the
Smithsonian's National Museum of Natural History and chair of
the Institute of Biology at the Scientific