Data from: Ovarian fluid allows directional cryptic female choice despite external fertilization

In species with internal fertilization, females can favour certain males over others, not only before mating but also within the female's reproductive tract after mating. Here, we ask whether such directional post-mating (that is, cryptic) female mate choice can also occur in species with external fertilization. Using an in vitro sperm competition experiment, we demonstrate that female ovarian fluid (ovarian fluid) changes the outcome of sperm competition by decreasing the importance of sperm number thereby increasing the relative importance of sperm velocity. We further show that ovarian fluid does not differentially affect sperm from alternative male phenotypes, but generally enhances sperm velocity, motility, straightness and chemoattraction. Under natural conditions, female ovarian fluid likely increases the paternity of the preferred parental male phenotype, as these males release fewer but faster sperm. These results imply females have greater control over fertilization and potential to exert selection on males in species with external fertilization than previously thought possible.Alonzo_et_al_Nature_Comm_2016_Expt1This file contains the data from Experiment 1 (the "in vitro" sperm competition experiments. These data are represented in Figures 1 and 2 and Tables 1 and 2.Alonzo_et_al_Nature_Comm_2016_Expt2This file contains the data from Experiment 2 (the experiment examining the effect of ovarian fluid on sperm characteristics). These data are represented in Figure 3.Alonzo_et_al_Nature_Comm_2016_Expt3This file contains the data from Experiment 3 (the experiment examining the effect of ovarian fluid on sperm chemoattraction). These data are represented in Figure 4