The probability of detecting multiple paternity (PrDM) for different mating scenarios (from two to ten males) for the three sites along the Biobío River: Upper Biobío (UBB), Mid Biobío (MBB), and mouth of the river (MoBB).

This was determined by PrDM simulations involving 21 progeny sampled per clutch and a minimum of seven microsatellite markers. The simulated mating scenarios were based on the minimum and maximum number of sires reported by other studies of aquatic gastropods, and the relative male contribution (equal, moderately skewed, or highly skewed) of males to the brood was varied.