title: The ontogeny of ultraviolet photosensitivity in rainbow trout (Salmo gairdneri).
abstract: The present study examines the changes in ultraviolet (UV) photosensitivity that occur during the growth of rainbow trout (Salmo gairdneri). A comparison of the ocular media transmission of small (n = 3) and large (n = 3) trout eyes did not reveal large changes in the transmission of UV radiation through the eye. We used the heart-rate conditioning technique to measure spectral sensitivity in immobilized trout. Four trout, each weighing less than 30 g, exhibited a UV-sensitivity peak at 360 nm while four additional trout weighing more than 60 g each exhibited no evidence of UV sensitivity. Spectral-sensitivity measurements of two trout weighing 44 g and 60 g revealed UV sensitivity, but when measured one month later (after a 25% increase in body weight) both fish exhibited no UV-sensitivity peak. At this time their sensitivity appeared to conform to the known blue-sensitive cone mechanism.
authors.affiliation: Department of Psychology, McMaster University, Hamilton, Ontario, Canada.
authors.forename: C W
authors.initials: CW
authors.lastname: Hawryshyn
authors.forename: M G
authors.initials: MG
authors.lastname: Arnold
authors.forename: D J
authors.initials: DJ
authors.lastname: Chaisson
authors.forename: P C
authors.initials: PC
authors.lastname: Martin
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D005123:Eye / Q000254:growth & development / Q000528:radiation effects*; D014337:Trout / Q000254:growth & development / Q000502:physiology*; D014466:Ultraviolet Rays