Male insemination decisions and sperm quality influence paternity in the golden orb-weaving spider

Abstract

In polyandrous species, paternity may be influenced by the timing and frequency of mating. Female spiders possess 2 genital openings that lead to separate sperm-storage structures. Thus, even when mating with a previously mated female, a male may reduce direct sperm competition by inseminating the opposite opening to her first mate. Such morphology may provide females with greater control over paternity. We examined simultaneously whether males avoided already inseminated female genital openings and whether this behavior varied with the time between successive matings. To explore these questions, we mated female golden orb weaver spiders, Nephila edulis, each to 2 males and manipulated the t..