Complementary left and right eye use during predator inspection and shoal-mate scrutiny in minnows

Minnows Phoxinus phoxinus did not show any difference in the average distance from a predator associated with the left or right position of a shoal-mate. While inspection behaviour of fish tested with a mirror on their left side was indistinguishable from the behaviour of controls tested without a mirror, inspection behaviour of fish tested with the mirror on their right side appeared to be changed and incoherent in both temporal and spatial parameters. These results suggest that, as in mosquitofish Gambusia holbrooki, the condition with the mirror on the left provided the best arrangement of monocular lateral stimulation in which each stimulus fell into the correct lateral visual field. Minnows showed a significant left eye preference during scrutiny of their mirror image when tested in the absence of any predator and a significant right eye preference while monitoring a live predator in the absence of a social partner. © 2002 The Fisheries Society of the British Isles. Published by Elsevier Science Ltd. All rights reserved.