Fig. 3. Comparison of female preference according to light-filter type. Exps 1 and 3 were control experiments conducted in the absence of other conspecifics, and tested the preferences of non-reproductive and sexually receptive females, respectively. Exp. 2 tested when small shoals of conspecifics could be viewed through the two filter types. Exp. 4 tested preference when sexually responsive males could be viewed (***P<0.01). In all four experiments, preference is denoted by the proportion of time each individual spent in either of the two preference zones (UV+/UV–) where the fish was facing towards the choice compartments during the 20 min test. Values are means ± S.E.D. (N=10).