South American spider females pick their mates according to how well the nuptial gift is wrapped

Feb 03, 2014
This photo shows a Paratrechalea ornata male offering a nuptial gift to a female. Credit: Mariana Trillo

It's not only what's inside the nuptial gift that a potential suitor brings to a female Paratrechalea ornata spider that counts. It's the whole package, white silk wrappings and all, that can give one male spider the edge over another. So say Mariana Trillo, Valentina Melo-González and María José Albo of the Instituto de Investigaciones Biológicas Clemente Estable in Uruguay, who carried out the first study to look at the role of silk wrappings during the courtship and mating of this South American semi-aquatic spider. The findings were published in the journal Naturwissenschaften – The Science of Nature.

The Paratrechalea ornata is one of many animals and especially invertebrates that use nuptial gift-giving during courtship and mating. During mate searching, of this species walk with vibrating forelegs and feeler-like pedipalps, while carrying prey wrapped in white in their mouth parts.

To find out more about this ceremony, Trillo's team collected spiders from the Santa Lucia River in Uruguay and ran a set of experiments in their laboratory in Montevideo. In one experiment, the mouth parts of some males were painted white, and others not. Females exposed to males with white mouth parts were more active, showed more physical contact and spent more time in front of them. They also accepted the matings earlier, and with more frequency than those exposed to males without paint.

The researchers therefore believe that the white coloring of the silk itself holds the big appeal for female spiders. This highlights the importance of visual cues during courtship and mate choice in Paratrechalea ornata. Also, Trillo's team does not believe that white is just a random choice for this spider. Members of this species are most active during sunset and at night, when bright or white objects stand out over longer distances compared to black ones. The white wrapping therefore could make it easier for a female to spot a male over a distance and to see if he is carrying a gift or not.

Trillo's team also found that gift wrapping is indeed a way in which females can judge a male's , and therefore its suitability to mate with. Males in poor condition produced poorly constructed and wrapped gifts, while males in better shape added more silk to the package, which made it also appear whiter.

"Females evaluate the physical condition of a male based on his silk wrapping performance, and how the gifts he brings look," Trillo summarizes. "Also, silk wrapping is a condition dependent trait and most probably allows a Paratrechalea ornata female to acquire information about her potential mate, including body condition and quality."

Explore further: Female spiders prefer the sperm of gift-bearing males

More information: Trillo, M.C. et al. (2014). Silk wrapping of nuptial gifts as visual signal for female attraction in a crepuscular spider, Naturwissenschaften – The Science of Nature. DOI: 10.1007/s00114-013-1139-x

Related Stories

Reversal of the black widow myth

May 06, 2013

The Black Widow spider gets its name from the popular belief that female spiders eat their male suitors after mating. However, a new study has shown that the tendency to consume a potential mate is also true of some types ...

Female cowbirds prefer less intense male courtship displays

May 03, 2012

In most species, females prefer the most intense courtship display males can muster, but a new study finds that female cowbirds actually prefer less intense displays. The full results are published May 2 in the open access ...

Male black widows look for well-fed mates

Jul 07, 2011

(PhysOrg.com) -- According to a new study published in Animal Behaviour, a male black widow spider is able to identify a female spider that has eaten well by simply taking a few steps on the web she spins. ...

Feast or fancy? Black widows shake for love

Jan 16, 2014

(Phys.org) —A team of Simon Fraser University biologists has found that male black widow spiders shake their abdomens to produce carefully pitched vibrations that let females know they have "come a-courting" ...

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

20 hours ago

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...