Center for Marine Biodiversity and Conservation

Stressors since the 1970s like overfishing and habitat degradation, have led to a decline in global shark and ray populations. Direct and indirect fishing pressures on shark populations have reduced the potential suitors for female sharks, while environmental changes may further worsen the ability of most shark species populations to rebound. Limited understanding of shark ecology impedes conservationists’ ability to create plans and influence policy. Convenience polyandry was thought to be a rare mating method found with sharks, with the common mechanism involving females accept copulation with any male to avoid excessive harassment. Despite the varied modes of reproduction, multiple paternity behavior in sharks has been recorded in seven elasmobranch orders. Recent studies have increasingly focused on the mechanism behind female choice and physiology in mating interactions generally displayed in post copulatory sperm selection mechanisms focused on “cryptic female choice”. In this study we considered a variety of potential drivers of multiple paternity. The models determined that phylogenetic distance is not the only driver of polyandry in sharks. That life history characteristics do hold some influence over the rate of multiple paternity.