title: UVB radiation affects growth, reproduction and tissue structure of Daphnia magna across several temperatures.
abstract: We examined the effects of daily exposure to UVB on growth, reproduction and histological characteristics of Daphnia magna over two generations at 20, 22, 25 and 30°C. Animals were exposed to 16 h of UVA and photosynthetically active radiation daily. Treated animals received 6 h of UVB during the light phase. Parental (P) generation growth and reproduction was impaired by exposure to UVB at all temperatures, with the poorest production at 30°C. First brood size decreased with UVB exposure; it was lowest at 30°C. Although F1 length at birth increased with P generation age, F1 produced by UVB-exposed mothers were smaller at all temperatures. The F1 generation was followed at 20 and 25°C; at both temperatures UVB exposure reduced F1 growth and reproduction. F1 growth and F2 production were lowest when both P and F1 generations were exposed to UVB. UVB exposure damaged ovarian and gut tissue at both 25 and 30°C; the consequences of this exposure were more severe at 30°C. The observed tissue damage may relate directly to the UVB-induced impairment of growth and reproduction. This study provides new insights into the effects of UVB on an important component of the pelagic zooplankton.
authors: Department of Biology, University of Winnipeg, Winnipeg, MB, Canada. j.huebner@uwinnipeg.ca
authors: Judith D
authors: JD
authors: Huebner
authors: Nancy L
authors: NL
authors: Loadman
authors: Murray D
authors: MD
authors: Wiegand
authors: Erwin
authors: E
authors: Huebner
authors: Daniel J
authors: DJ
authors: Palitsky
authors: William H
authors: WH
authors: Husarewycz
mesh_terms: D000818:Animals; D049628:Body Size / Q000528:radiation effects; D003621:Daphnia / Q000254:growth & development / Q000528:radiation effects*; D005298:Fertility / Q000502:physiology / Q000528:radiation effects*; D012098:Reproduction / Q000502:physiology / Q000528:radiation effects*; D013696:Temperature; D014466:Ultraviolet Rays