A two‐second delay confers first‐male fertilization precedence within <i>in vitro</i> sperm competition experiments in Atlantic salmon

In vitro paired‐male sperm competition experiments in Atlantic salmon Salmo salar for a single female’s eggs revealed that 2 s delays in sperm release caused significant reductions in paternity, with second males achieving only 30% fertilization success (against an expected 50%). This first‐male fertilization precedence supports previous work suggesting that sperm competition follows the principles of a race in Atlantic salmon, and suggests that any timing asymmetry in sperm release within natural competitive spawnings could have significant consequences for male fertilization success.