Successive matings affect copulatory courtship but not sperm transfer in a spider model

Abstract

Previous studies have reported that males augment their reproductive success by increasing the number of females with which they copulate, and that such copulations are not energetically demanding in terms of trivial sperm production costs. However, we now know that males do pay reproductive costs. As males mate successively, a reduction in the performance of copulatory behaviours would be expected, as well as in the number of sperm transferred. Here we compared the duration of courtship, mating and post-insemination phase, the number of genital and non-genital copulatory courtship occurrences, and the number of sperm transferred in successive matings in Holocnemus pluchei spider males. As matings increased in males, there was no effect on the duration of courtship, mating or post-insemination phase. Interestingly, genital copulatory courtship varied in successive copulations depending on male size, but there was no change in the number of sperm transferred. In addition, the occurrence of non-genital copulatory courtship decreased along successive copulations. The negative effects of successive matings on copulatory courtship indicate that these behaviours are costly for males, except for the number of sperm transferred. Our research lays the foundation for future studies on male costs as a function of mating history in spiders.

Evolutionary morphology of sperm in pholcid spiders (Pholcidae, Synspermiata)

“…For example, pholcid spiders show an interesting reproductive biology with different reproductive strategies, many sexual dimorphisms, and a high disparity of genitalic structures including asymmetry, genital polymorphism, and fundamentally different configurations of the female internal genitalia (e.g. [ 2 , 8 – 15 ]). In contrast to the vast knowledge on the gross morphology of female and male genitalia, the primary male reproductive system is severely understudied.…”