A comparison of the effects of long-term β- and γ-irradiation on the reproductive performance of a marine invertebrate Ophryotrocha diadema (Polychaeta, Dorvilleidae)

The effects of chronic exposure to the same absorbed dose rates of β-radiation from tritiated water, or γ-radiation from an external 137Cs source, on the reproductive performance of the polychaete Ophryotrocha diadema have been compared. At 7.3 mGyh−1, both β- and γ-radiation caused similar, significant reductions in numbers of larvae compared with controls. The γ-irradiated worms had significant reductions in egg production, but not in the survival of eggs to larvae, while β-irradiated worms had significant reductions in the survival of eggs to larvae, but not in egg production. There was no evidence for the high radiosensitivity to β-radiation reported for some other invertebrates.