Barki, A., Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
Zion, B., Institute of Agricultural Engineering, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
Shapira, L., Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
Karplus, I., Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel

A substantial proportion of newborns are lost in guppy hatcheries to cannibalism by the broodfish although small-mesh baskets, which allow passage to small fry only and provide a predation-free area, are used in breeding tanks. If newborn guppies are attracted by light, illuminating the small-mesh baskets might enhance aggregation of newborns in the mesh basket and thus mitigate cannibalism effect. In this study, light attraction and light colour preference in newborn guppies were investigated. Testing the attraction to white, blue, green and red LED lights revealed attraction to each of these light types in newborns, but no significant attraction in adult females. Both newborns and adult females exhibited reduced mobility under red LED light. In a preference experiment in which all light colours were presented simultaneously, newborns were most attracted to the white light (52.0% of the newborns) and least attracted to the red light and darkness (6.8% and 6.7% of the newborns respectively). These results support the potential efficacy of using white light to attract newborns into the baskets in guppy breeding tanks and reduce cannibalism effects. © 2012 John Wiley & Sons Ltd.