Results of Experiment 1. The graph shows the fishes frequency of choice (means with SEM), in terms of number of approaches at the geometrically correct diagonal (C + R) vs. the incorrect one (N + F), during five consecutive daily sessions in a transparent version of the social cued memory task, without exploration times. As shown in the schematic drawing, the geometrically correct corners are indicated with letter “C” (the correct corner) and letter “R” (the rotationally correct corner, on the same diagonal), while the incorrect corners are indicated with letter “N” (near the correct C) and letter “F” (far from the correct C). Black lines are referred to first approaches for all fishes together, yellow lines to approaches made by zebrafish, blue lines to approaches by redtail splitfin fish, red lines to approaches by goldfish. All fishes were not able to solve the social cued memory task – to encode the environmental shape in relation to a specific goal – in absence of extra-visual experience (i.e., through the lateral line and/or the sense of touch). Moreover, the number of zebrafish approaches is greater than that of the other two species considered.