Attractive effects of different light intensities on Hypophthalmichthys molitrix and Ctenopharyngodon idellus

We studied the attractive effects of the light source located in lock model on Hypophthalmichthys molitrix and Ctenopharyngodon idellusat different light intensities. The results show that the mean relative time aggregation rate R(t) in the dark area with light source was higher than the control group (no source). R(t) in the dark area in all light-source groups increased with increasing light intensity, and so did the distance between central location of fish group and location of light source. As for the H. molitrix, there was no obvious aggregation phenomenon (P0.05) in all groups. Therefore, negative phototaxis of C.idellus could be used in driving the fish to the upstream by arranging light in the downstream of the chamber, but use of light trapping or driving H. molitrixis not feasible.