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 Matjaž Kuntner, research associate at the Smithsonian's National Museum of Natural History and chair of the Institute of Biology at the Scientific Research Centre, Slovenian Academy of Sciences and Arts; Daiqin Li, associate professor at the Department of Biological Sciences, National University of Singapore, and doctoral students Matjaž Gregoriè and Shichang Zhang, and postdoc Simona Kralj-Fišer.
Before the trials the researchers speculated that the additional mystery plugs commonly found covering female genitals might be produced by the copulating male, or the female, or perhaps both spider sexes. The researchers tested these possibilities by staging laboratory mating trials with varying degrees of females mating with multiple males. They observed that no plugs were ever formed during mating trials, but instead, females exposed to many males produced the amorphous plugs during the egg-laying process.
These plugs, when hardened, prevented subsequent copulation. The authors conclude that the newly discovered "self-plugging" mechanism represents a female adaptation to sexual conflict through the prevention of unwanted and excessive copulations.
John Gibbons | EurekAlert!
Antibiotics: New substances break bacterial resistance
12.11.2019 | Martin-Luther-Universität Halle-Wittenberg
How the Zika virus can spread
11.11.2019 | Goethe-Universität Frankfurt am Main
If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.
Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...
Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...
In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.
An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...
An international research group has observed new quantum properties on an artificial giant atom and has now published its results in the high-ranking journal Nature Physics. The quantum system under investigation apparently has a memory - a new finding that could be used to build a quantum computer.
The research group, consisting of German, Swedish and Indian scientists, has investigated an artificial quantum system and found new properties.
Researchers at the U.S. Department of Energy's (DOE) Argonne National Laboratory have reported a new mechanism to speed up the charging of lithium-ion...
05.11.2019 | Event News
30.10.2019 | Event News
02.10.2019 | Event News
12.11.2019 | Machine Engineering
12.11.2019 | Power and Electrical Engineering
12.11.2019 | Physics and Astronomy