Featured Research

from universities, journals, and other organizations

Male dwarf spiders make sure offspring is their own

Date:
June 10, 2014
Source:
Springer Science+Business Media
Summary:
Chastity belts were not first thought out in mediaeval times -- members of many animal groups have evolved similar mechanical safeguards to ensure their paternity. Male dwarf spiders, for instance, use mating plugs to block off the genital tract of the female they have just mated with. The larger and older the plug, the better the chances are that other males will not make deposits in a female's sperm storage organ.

Ventral view of an Oedothorax retusus female. Red square indicates the position of the genital region (epigyne) that is plugged by the male.
Credit: Melanie Witthuhn

Chastity belts were not first thought out in mediaeval times -- members of many animal groups have evolved similar mechanical safeguards to ensure their paternity. Male dwarf spiders, for instance, use mating plugs to block off the genital tract of the female they have just mated with. The larger and older the plug, the better the chances are that other males will not make deposits in a female's sperm storage organ, too. So says Katrin Kunz and co-authors of the Zoological Institute and Museum in Greifswald, Germany, in an article published in Springer's journal Behavioral Ecology and Sociobiology about this European spider.

This study builds on previous research led by co-author Gabriele Uhl that showed that dwarf spider males (Oedothorax retusus) insert mating plugs into the two copulatory ducts of the females they have mated with.

Kunz and her colleagues took these findings one step further to study just how well the mating plugs of the dwarf spider work. They discovered that the material the plugs are made of is transferred in a liquid state from the male to the female and that it needs to harden to a certain degree before it can withstand penetration or removal by a rival male. Remating trials were then staged after females received plugs of different sizes during a first round of copulation. Their effectiveness over periods of time was also tested. The female spiders were then scrutinized under a scanning electron microscope.

Overall, small plugs were found to be less effective than large plugs. This suggests that smaller portions of the translucent plug material can be more easily removed or overcome by a subsequent male that wants to mate. Small plugs are also least effective shortly after they are placed, which suggests that both size and the hardening of the material plays an important role in how well the plug works. Once plugs are older than a day they strongly serve to monopolize access to the duct that leads to the female sperm storage organ.

However, even if subsequent males are able to mate, at least part of their sperm mass remains outside of the female genital tract, confirming the efficacy of the mating plug. Consequently, if a male succeeds in plugging both of the female's copulatory openings, his paternity success is expected to be very high.

"The mating plug in the dwarf spider clearly functions as a mechanical obstacle to rival males," says Kunz. "Mating plugs are a powerful mechanical safeguard whose efficacy varies with plug size and age."


Story Source:

The above story is based on materials provided by Springer Science+Business Media. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kunz, K. et al. Does the size and age of mating plugs alter their efficacy in protecting paternity? Behavioral Ecology and Sociobiology, June 2014 DOI: 10.1007/s00265-014-1742-7

Cite This Page:

Springer Science+Business Media. "Male dwarf spiders make sure offspring is their own." ScienceDaily. ScienceDaily, 10 June 2014. <www.sciencedaily.com/releases/2014/06/140610101842.htm>.
Springer Science+Business Media. (2014, June 10). Male dwarf spiders make sure offspring is their own. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2014/06/140610101842.htm
Springer Science+Business Media. "Male dwarf spiders make sure offspring is their own." ScienceDaily. www.sciencedaily.com/releases/2014/06/140610101842.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Rare Lion Cubs Make Debut at Belgrade Zoo

Raw: Rare Lion Cubs Make Debut at Belgrade Zoo

AP (Oct. 17, 2014) Two white lion cubs were born in Belgrade zoo three weeks ago. White lions are a rare mutation of a species found in South Africa and some cultures consider them divine. (Oct. 17) Video provided by AP
Powered by NewsLook.com
The Best Foods To Boost Your Mood

The Best Foods To Boost Your Mood

Buzz60 (Oct. 17, 2014) Feeling down? Reach for the refrigerator, not the medicine cabinet! TC Newman (@PurpleTCNewman) shares some of the best foods to boost your mood. Video provided by Buzz60
Powered by NewsLook.com
Sweet Times for Hard Cider Makers

Sweet Times for Hard Cider Makers

AP (Oct. 16, 2014) With hard cider making a hardcore comeback across the country, craft makers are trying to keep up with demand and apple growers are tapping a juicy new revenue stream. (Oct. 16) Video provided by AP
Powered by NewsLook.com
Meet Garfi the Angry Cat

Meet Garfi the Angry Cat

Buzz60 (Oct. 16, 2014) Garfi is one frowny, feisty feline - downright angry! Ko Im (@koimtv) introduces us to the latest animal celebrity taking over the Internet. You can follow more of Garfi's adventures on Twitter (@MeetGarfi) and Facebook (Garfi). Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins