title: Environmental light color affects the stress response of Nile tilapia.
abstract: We investigated the effects of environmental light colors (blue, yellow and white) on the stress responses (measured by changes in ventilatory frequency - VF) of Nile tilapia to confinement. After 7 days of light treatment, the VF was similar for fish in each color. On the 8th day, fish were confined for 15 min. After release, the post-confinement VF was measured six times (first period: 0, 2 and 4 min; second period: 6, 8 and 10 min). Irrespective of the light color treatment, confinement increased the VF to higher levels during the first post-confinement period than during the second one. When color was analyzed, irrespective of time, fish under white light increased their VF post-confinement, and blue light prevented this effect. We conclude that blue light is the preferred color for Nile tilapia in terms of reducing stress. This finding is in contrast to previous choice test studies that indicated that yellow is their preferred color.
authors.affiliation: Laboratory of Animal Physiology and Behavior, Departamento de Fisiologia, Instituto de Biociências (IBB)/CAUNESP, UNESP, Botucatu, SP, Brazil.
authors.forename: Caroline Marques
authors.initials: CM
authors.lastname: Maia
authors.forename: Gilson Luiz
authors.initials: GL
authors.lastname: Volpato
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002755:Choice Behavior / Q000528:radiation effects; D023681:Cichlids / Q000502:physiology*; D003116:Color; D004777:Environment; D008027:Light; D010101:Oxygen Consumption / Q000528:radiation effects*; D013312:Stress, Physiological / Q000528:radiation effects*