Spiders Try to Ensure Paternity

Male dwarf spiders deploy sperm-blocking plugs to thwart the reproductive chances of their mate’s subsequent suitors.

By | June 11, 2014

Ventral view of an Oedothorax retusus female. Red square indicates the position of the genital region (epigyne) that is plugged by the male.MELANIE WITTHUHNThe plugs that male dwarf spiders (Oedothorax retusus) insert into the copulatory ducts of females with whom they’ve just mated act to block fertilizations by other males, according to researchers studying the arthropods. “The mating plug in the dwarf spider clearly functions as a mechanical obstacle to rival males,” lead author Katrin Kunz of the Zoological Institute and Museum in Greifswald, Germany, said in a statement. “Mating plugs are a powerful mechanical safeguard whose efficacy varies with plug size and age.”

Kunz and her coauthors, who’s study of the spider’s mating habits was published yesterday (June 10) in Behavioral Ecology and Sociobiology, determined that the mating plugs are composed of a liquid material that hardens with time to block access to females’ sperm storage organs shortly after they’ve copulated. When the researchers mated females bearing such plugs to subsequent males only about 32 percent resulted in successful copulation. And the chances of a rival male’s sperm reaching the sperm storage organ of the female decreased the longer the plug had to dry and harden in the genital openings. The team also discovered that larger plugs were more effective at blocking subsequent fertilizations than were smaller ones, which males had an easier time punching through or removing.

Add a Comment

Avatar of: You

You

Processing...
Processing...

Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo

Popular Now

  1. Running on Empty
    Features Running on Empty

    Regularly taking breaks from eating—for hours or days—can trigger changes both expected, such as in metabolic dynamics and inflammation, and surprising, as in immune system function and cancer progression.

  2. Athletes’ Microbiomes Differ from Nonathletes
  3. Mutation Linked to Longer Life Span in Men
  4. Gut Feeling
    Daily News Gut Feeling

    Sensory cells of the mouse intestine let the brain know if certain compounds are present by speaking directly to gut neurons via serotonin.

AAAS