Additional file 2 of Evolution and co-evolution of the suck behaviour, a postcopulatory female resistance trait that manipulates received ejaculate

Additional file 2. Movie S2. Behavioural instances in reciprocally mating species where the mating posture deviates from that observed in M. lignano . Note that the movies are recorded at one frame per second, but played back at a rate of ten frames per second, i.e. a 1:10 time lapse. See the inset time stamp for the absolute timing (full movies will be available online in a public data repository). A. Macrostomum sp. 59 In this movie clip, there are two drops with three worms in each drop. In the left drop, two worms, soon after the start of the movie, start mating reciprocally. This is visible as the two worms being intertwined, such that the female antrum was accessible to the partner's stylet and vice-versa. This was followed by brief sucks by both individuals, and then they separated. After some time, they briefly mate reciprocally again, followed by both individuals sucking. B. Macrostomum sp. 61 In this movie clip, there are two drops with three worms in each drop. In the left drop, two worms mate reciprocally by intertwining. However, they then partially untwined, such that they resembled a pretzel with both worms’ anterior part facing in the same direction.