Lek-Like Spawning Behaviour and Different Female Mate Preferences in Roach (Rutilus Rutilus)

I studied the scarcely known mating system of roach. Individually marked fish were kept in a pond with a glass wall that allowed observations of spawning. The roach showed a lek-like mating system which has not been described previously, with bourgeois males and reproductive parasites (i.e. simultaneous parasitic spawning), both tactics used by the same individuals. Females had the possibility to choose freely among the males but could probably hardly avoid multi-male fertilization. Most females spawned repeatedly during the observation period. They showed strong individual preferences with different females preferring different males or spawning sites.