Tag : Sperm

Washington: Male spiders have evolved behavioural mating strategies to improve their chances of mating despite the risk of being cannibalised by their mates. Researchers from the National University of Singapore (NUS) have discovered that male spiders make choices on maximising their mating success when they are at risk of being cannibalised by their female mates. They published their findings in Communications Biology. Led by Associate Professor Li Daiqin from the NUS Department of Biological Sciences, the researchers found that a male chooses one of its paired sexual organs with more sperm for the first copulation with a cannibalistic female. Also, a male transfers significantly more sperm if a female is cannibalistic or when the female is of a much larger physical size. Increasing sperm transfer in the face of sexual cannibalism The theory of the male mating syndrome posits that male spiders are under sexual conflict pressure in sexually cannibalistic situations, as they may only have a single chance to mate. In this study, the researchers explored whether male spiders use additional cannibalism countering strategies by focusing on two male mating tactics. One of which is the "better-charged palp" hypothesis which predicts that male spiders selectively make use of one of their paired sexual organs, known as pedipalps or palps, containing more sperm for their first copulation. The other, referred to as the "fast sperm transfer" hypothesis, predicts accelerated insemination when the risk of female cannibalism is high. The researchers performed comparative tests on five species of orb-web spiders from Singapore with varying levels of female sexual cannibalism and sexual size dimorphism. They found that male spiders choose one of t ...