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Better gifts, better sex for spiders

Oct. 27, 2013
Courtesy of Aar­hus Uni­vers­ity
and World Science staff

A male spi­der that gives its cho­sen female a nup­tial gift gets to mate with her for a long­er time and there­by boost his chances of fa­ther­ing off­spring, a study has found.

Ma­ria J. Albo and col­leagues at Aar­hus Uni­vers­ity in Den­mark ex­am­ined the habits of the gift-giving spi­der, Pi­sau­ra mira­bilis.

This vi­deo be­gins by show­ing a male wrap­ping up a fly. He then pre­s­ents it to the female and trans­fers sperm. The male sub­se­quent­ly plays dead and is dragged away by the fema­le. He then ends up as food for the fema­le, which has killed him. This takes place in about 2 per­cent of mat­ings. (Cred­it: Cristina Tuni)


Many males of the spe­cies to the trou­ble of find­ing a tasty gift, such as a dead fly, wrap­ping it up nicely in spi­der silk and of­fer­ing it to a female they would like to mate. The gift-givers have far bet­ter chances of fa­ther­ing the fema­le’s off­spring than those who skip the pre­s­ent, the sci­en­tists found.

While the female eats the gift, the male trans­fers sperm to a spe­cial or­gan in her body, where it can be used to fer­ti­lize eggs. The re­search­ers found that the female stores more sperm if the male has brought a gift, and he is there­fore more likely to be the fa­ther of her off­spring. The fema­le, there­fore, can ev­i­dently con­trol how much sperm she stores, fa­vor­ing gift-giving ma­les, the sci­en­tists ex­plained.

In a small per­cent­age of cases, females ac­tu­ally eat the male af­ter sex.

The fema­le, the sci­en­tists added, pre­sumably prefers sperm from the gift bear­er be­cause it shows he is re­source­ful and a good hunt­er. If these are ge­net­ic traits, the female can pass the qual­i­ties to her off­spring by fa­vor­ing the ma­le. The female spi­der thus se­lects sperm from the males she prefers.

The study was pub­lished Oct. 23 in the jour­nal Pro­ceed­ings of the Roy­al So­ci­e­ty B.


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A male spider that gives its chosen female a nuptial gift gets to mate with her for a longer time and thereby boost his chances of fathering offspring, a study has found. Maria J. Albo and colleagues at Aarhus University in Denmark examined the habits of the gift-giving spider, Pisaura mirabilis. Many males of the species to the trouble of finding a tasty gift, such as a dead fly, wrapping it up nicely in spider silk and offering it to a female they would like to mate. The gift-givers have far better chances of fathering the female’s offspring than those who skip the present, the scientists found. While the female eats the gift, the male transfers sperm to a special organ in her body, where it can be used to fertilize eggs. The researchers found that the female stores more sperm if the male has brought a gift, and he is therefore more likely to be the father of her offspring. The female, therefore, can evidently control how much sperm she stores, favoring gift-giving males, the scientists explained. In a small percentage of cases, females actually eat the male after sex. The female, the scientists added, presumably prefers sperm from the gift bearer because it shows he is resourceful and a good hunter. If these are genetic traits, the female can pass the qualities to her offspring by favouring the male. The female spider thus selects sperm from the males she prefers. The study was published Oct. 23 in the journal Proceedings of the Royal Society B.