Relationship between pre- and post-copulatory traits in Salvator rufescens (Squamata: Teiidae)

Abstract

Understanding pre- and post-copulatory mechanisms of sexual selection can provide insights into the evolution of male reproductive strategies. The phenotype-linked fertility hypothesis postulates that male sperm quality and secondary sexual characteristics will positively co-vary, whereas the sperm competition hypothesis predicts a negative association between those traits. Male reproductive traits often show variation throughout the reproductive period, suggesting that the relationship between pre- and post-copulatory sexual selection may vary temporally. Here, we evaluated the relationship between secondary sexual character and sperm traits and its temporal variation in Salvator rufescens, a south American lizard. We observed a negative relationship between jaw muscle and principal piece length of sperm and a variation in the relationship between pre- and post-copulatory traits throughout the reproductive period. Collectively, our results evidenced a trade-off between pre- and post-copulatory traits and a strong seasonal flexibility of male reproductive strategies in this lizard species.