<p dir="ltr">This dataset consists of three different files. The first one [<b>Mate-choice data (all pops and treatments)</b>] provides all the association times as a function of species, population, salinity level, as well as fish size. The second (<b>SOP large vs small male</b>) provides all association times as well as Strength of Preference score (SOP) for all trials that provided a choice between a large and a small male. The third (<b>SOP parasitised vs nonparasitised male</b>) provides association times as well as Strength of Preference score (SOP) for all trials that provided a choice between a parasitised and a nonparasitised male.</p>