Effects of chronic external gamma irradiation on growth and reproductive success of Daphnia magna
Résumé
Aquatic invertebrates (water flea Daphnia magna) were exposed to low dose rates of external gamma radiation (from 0.4 to 31 mGy h-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 31 mGy h-1 than in the control. Reproduction was affected through early release and reduced size of broods after 15 days of exposure at 31 mGy h-1 (broods 3-5), resulting in a 21% fecundity decrease at 31 mGy h-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. © 2007 Elsevier Ltd. All rights reserved.
Mots clés
reproductive success
respiration
survival
toxicity
alpha radiation
animal experiment
article
controlled study
Daphnia
fertility
gamma irradiation
long term exposure
newborn
nonhuman
radiation dose
radiation injury
radiosensitivity
reproductive toxicity
starvation
toxicity testing
Animals
Gamma Rays
Larva
Reproduction
Cladocera
Daphniidae
Invertebrata
Energy balance
Gamma rays
Growth kinetics
Respiratory mechanics
Daphnia magna
Gamma irradiation
Radioprotection of environment
Biodiversity
comparative study
crustacean
fecundity
gamma ray radiation
growth response
irradiation
radiation exposure