Fig. 1.

The Definition of ETR (A) and ETR versus OMR (B). (A) We defined one ETR as when the head of the goldfish in the fish bowl starts to turn as the fish tracks a single edge of the black/red square wave pattern and turns at least 90 degrees (left side of Fig. 1A in circle) from the initial direction of head. The initial position of the goldfish is indicated by the lightest drawing, the next position is a darker drawing, and the last position is the darkest drawing (the point when the goldfish turned 90 degrees). On the right side of fig. 1a, the overlapped three stages of one goldfish ETR are shown separately from top to bottom. (B) A correlation graph between OMR and ETR from experiments with 50 goldfish. Both OMR and ETR were in a wide range from 1 to 12 or 20% to 75% and had mean values of OMR=43.47±4.34% and ETR=6.38±2.91.