Male (right) and female (left) Pisaura mirabilis spiders grabbing the nuptial gift during matingMARIA ALBOFor the spider Pisaura mirabilis, sex and a meal make a great deal. During courtship, the male presents the female with a food item—called a nuptial gift—and as she feeds, he deftly transfers his sperm into her. However, females will also accept males without gifts. Why, then, should males bother?
Because the fate of his sperm depends on it.
A new study, published in Proceedings of the Royal Society B: Biological Sciences last week (October 23), reported that P. mirabilis females prefer sperm from males with gifts and store more of those gametes. Maria Albo and her colleagues at Aarhus University in Denmark counted sperm retained in newly mated P. mirabilis females and the number of eggs that hatched. Some male partners presented nuptial gifts, while others did not. Accounting for the effect of copulation time, Albo’s team found that females kept about 40 percent less sperm from non-gifting males compared with their gift-bearing counterparts. The researchers also found reduced egg-hatching rates from matings with males that did not present nuptial gifts. This suggested that ...