Fig. 7. Results of transfer tests with fish 1 (blue) and fish 2 (red), during which the training objects (pyramid, S+; cube, S–) were replaced by so-called wire objects of the same outline as the training objects (see text). (A) Photos of the wire objects (left) and of the wire objects embedded in electrically transparent agar with interrupted vertical parts (right). (B–D) Choice frequencies for the pyramid (S+) by fish 1 (blue) and fish 2 (red). Right bars, original training objects; left bars, wire objects (B), vertically interrupted wire objects (C) and vertically and horizontally interrupted wire objects (D). Asterisks above each graph indicate significant differences from random choice conditions: ^**P<0.01; n.s., non significant.