title: Effects of chronic external gamma irradiation on growth and reproductive success of Daphnia magna.
abstract: Aquatic invertebrates (water flea Daphnia magna) were exposed to low dose rates of external gamma radiation (from 0.4 to 31mGyh(-1)) over a 23-day period (i.e. 5 broods). Gamma radiation caused changes in neither survival nor somatic growth. Mass-specific respiration rate was significantly lower at 31mGyh(-1) than in the control. Reproduction was affected through early release and reduced size of broods after 15 days of exposure at 31mGyh(-1) (broods 3-5), resulting in a 21% fecundity decrease at 31mGyh(-1) compared to the control. A decreased resistance of neonates to starvation was observed in relation to dose rates. Possible mechanisms of gamma radiotoxicity for daphnid reproduction and implications for radioprotection are discussed.
authors.affiliation: IRSN, France. rodolphe.gilbin@irsn.fr
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Gilbin
authors.forename: Frédéric
authors.initials: F
authors.lastname: Alonzo
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Garnier-Laplace
mesh_terms: D000818:Animals; D003621:Daphnia / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects*; D005720:Gamma Rays; D007814:Larva; D012098:Reproduction / Q000528:radiation effects*